A-level Computing/AQA/Paper 1/Skeleton program/2024

This is for the AQA A Level Computer Science Specification.

This is where suggestions can be made about what some of the questions might be and how we can solve them.

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Section C Predictions

edit

The 2024 paper 1 will contain 3 questions worth 11 marks in total (one 3 marker one 2 marker and one 6 marker). As long as you know the program well i.e. that understanding each line of code and and you know what each line of code does, you can also do this by using Chatgpt and Gemini and its important you use all the tools availble to you, this will be dead easy. I'm predicting this year there will be a question on Inheritance about the cell and they will ask what it means so will be worth 3 marks. Also they could be a question on overriding and they could be a question about difference from the protected, private and public methods from looking at past papers.

Section D Predictions

edit

Programming Questions on Skeleton Program

  • The 2024 paper 1 contains 4 questions: a 5 mark, a 6 mark question and two 14 mark questions - these marks include the screen capture, so the likely marks for the coding will be 1-2 marks lower. On top of this, can someone please add some more solution in VB.net for these problems. Message for moderator - I added a question I think could come up please put a link up then delete this message - Thanks for such a brilliant resources you have provide for help for all students!
  • The 2023 paper 1 contains 4 questions: a 5 mark, a 9 mark question, a 10 mark question and one 13 mark question - these marks include the screen capture(s), so the likely marks for the coding will be 1-2 marks lower.
  • The 2022 paper 1 contained 4 questions: a 5 mark, a 9 mark question, a 11 mark question and one 13 mark question - these marks include the screen capture(s), so the likely marks for the coding will be 1-2 marks lower.
  • The 2021 paper 1 contained 4 questions: a 6 mark, an 8 mark question, a 9 mark question and one 14 mark question - these marks include the screen capture(s), so the likely marks for the coding will be 1-2 marks lower.
  • The 2020 paper 1 contained 4 questions: a 6 mark, an 8 mark question, a 11 mark question and one 12 mark question - these marks include the screen capture(s), so the likely marks for the coding will be 1-2 marks lower.
  • The 2019 paper 1 contained 4 questions: a 5 mark, an 8 mark question, a 9 mark question and one 13 mark question - these marks include the screen capture(s), so the marks for the coding will be 1-2 marks lower.
  • The 2018 paper 1 contained 5 questions: a 2 mark question, a 5 mark question, two 9 mark questions, and one 12 mark question - these marks include the screen capture(s).
  • The 2017 paper 1 contained 5 questions: a 5 mark question, three 6 mark questions, and one 12 mark question.

Current questions are speculation by contributors to this page.

Question 1 - Symbol Case [3 marks]

edit

Lower case symbols are not accepted. E.g. if you enter 'q' it is not recognized as 'Q'. Fix this.

C#:

Easy solution just add .ToUpper() and it will change your lowercase inputs to uppercase and allow them to work.}}

private string GetSymbolFromUser()
{
     string Symbol = "";
     while (!AllowedSymbols.Contains(Symbol))
     {
          Console.Write("Enter symbol: ");
          Symbol = Console.ReadLine().ToUpper();
      }
      return Symbol;
}


Delphi/Pascal:


Java:

    private String getSymbolFromUser() {
        String symbol = "";
        while (!allowedSymbols.contains(symbol)) {
            Console.write("Enter symbol: ");
            symbol = Console.readLine();
            symbol = symbol.toUpperCase(); //added line
        }
        return symbol;
    }


Python:

    def __GetSymbolFromUser(self):
        Symbol = ""
        while not Symbol in self.__AllowedSymbols:
            Symbol = input("Enter symbol: ").upper()
        return Symbol


VB.NET:

A simple solution, just add UCase to change all input to upper case.

  Private Function GetSymbolFromUser() As String
            Dim Symbol As String = ""
            While Not AllowedSymbols.Contains(Symbol)
                Console.Write("Enter symbol: ")
                Symbol = UCase(Console.ReadLine())
            End While
            Return Symbol
        End Function


Question 2 - Game file not existing [4 marks]

edit

If a filename is entered that does not exist, the game is unplayable (infinite loop). Amend the program so that in this case the default game is played, with a suitable message to indicate this.

C#:

static void Main(string[] args)
{
    string Again = "y";
    int Score;
    while (Again == "y")
    {
        Console.Write("Press Enter to start a standard puzzle or enter name of file to load: ");
        string Filename = Console.ReadLine();
        Puzzle MyPuzzle;
        if (Filename.Length > 0)
        {
            // new code for question 2 - use try/catch in main and otherwise cause default game to be played

            try
            {
                MyPuzzle = new Puzzle(Filename + ".txt");
            }
            catch
            {
                Console.WriteLine("Invalid file. Playing default puzzle instead.");
                MyPuzzle = new Puzzle(8, Convert.ToInt32(8 * 8 * 0.6));
            }
            // end of new code for question 2
        }
        else
        {
            MyPuzzle = new Puzzle(8, Convert.ToInt32(8 * 8 * 0.6));
        }
        Score = MyPuzzle.AttemptPuzzle();
        Console.WriteLine("Puzzle finished. Your score was: " + Score);
        Console.Write("Do another puzzle? ");
        Again = Console.ReadLine().ToLower();
    }
    Console.ReadLine();
}

// try/catch removed from loadPuzzle subroutine
private void LoadPuzzle(string Filename)
{

    using (StreamReader MyStream = new StreamReader(Filename))
    {
        int NoOfSymbols = Convert.ToInt32(MyStream.ReadLine());
        for (var Count = 1; Count <= NoOfSymbols; Count++)
        {
            AllowedSymbols.Add(MyStream.ReadLine());
        }
        int NoOfPatterns = Convert.ToInt32(MyStream.ReadLine());
        for (var Count = 1; Count <= NoOfPatterns; Count++)
        {
            List<string> Items = MyStream.ReadLine().Split(',').ToList();
            Pattern P = new Pattern(Items[0], Items[1]);
            AllowedPatterns.Add(P);
        }
        GridSize = Convert.ToInt32(MyStream.ReadLine());
        for (var Count = 1; Count <= GridSize * GridSize; Count++)
        {
            Cell C;
            List<string> Items = MyStream.ReadLine().Split(',').ToList();
            if (Items[0] == "@")
            {
                C = new BlockedCell();
            }
            else
            {
                C = new Cell();
                C.ChangeSymbolInCell(Items[0]);
                for (var CurrentSymbol = 1; CurrentSymbol < Items.Count; CurrentSymbol++)
                {
                    C.AddToNotAllowedSymbols(Items[CurrentSymbol]);
                }
            }
            Grid.Add(C);
        }
        Score = Convert.ToInt32(MyStream.ReadLine());
        SymbolsLeft = Convert.ToInt32(MyStream.ReadLine());
    }
}
}}


Delphi/Pascal:


Java:

//Change loadfile to return a boolean to say if it was successful

    private boolean loadPuzzle(String filename) {
        boolean success = true;
        try {
            File myStream = new File(filename);
            Scanner scan = new Scanner(myStream);
            int noOfSymbols = Integer.parseInt(scan.nextLine());
            for (int count = 0; count < noOfSymbols; count++) {
                allowedSymbols.add(scan.nextLine());
            }
            int noOfPatterns = Integer.parseInt(scan.nextLine());
            for (int count = 0; count < noOfPatterns; count++) {
                String[] items = scan.nextLine().split(",", 2);
                Pattern p = new Pattern(items[0], items[1]);
                allowedPatterns.add(p);
            }
            gridSize = Integer.parseInt(scan.nextLine());
            for (int count = 1; count <= gridSize * gridSize; count++) {
                Cell c;
                String[] items = scan.nextLine().split(",", 2);
                if (items[0].equals("@")) {
                    c = new BlockedCell();
                } else {
                    c = new Cell();
                    c.changeSymbolInCell(items[0]);
                    for (int currentSymbol = 1; currentSymbol < items.length; currentSymbol++) {
                        c.addToNotAllowedSymbols(items[currentSymbol]);
                    }
                }
                grid.add(c);
            }
            score = Integer.parseInt(scan.nextLine());
            symbolsLeft = Integer.parseInt(scan.nextLine());
        } catch (Exception e) {
            Console.writeLine("Puzzle not loaded");
            success = false;
        }
        return success;
    }

//Change the Puzzle(filename) constructor to load a default 8*8 puzzle if the filename is invalid

    public Puzzle(String filename) {
        grid = new ArrayList<>();
        allowedPatterns = new ArrayList<>();
        allowedSymbols = new ArrayList<>();
        if (!loadPuzzle(filename)) {
            //the puzzle could not be loaded - run normal game with default size and symbols
            score = 0;
            symbolsLeft = (int) (8*8*0.6);
            gridSize = 8;
            grid = new ArrayList<>();
            for (int count = 1; count < gridSize * gridSize + 1; count++) {
                Cell c;
                if (getRandomInt(1, 101) < 90) {
                    c = new Cell();
                } else {
                    c = new BlockedCell();
                }
                grid.add(c);
            }
            allowedPatterns = new ArrayList<>();
            allowedSymbols = new ArrayList<>();
            Pattern qPattern = new Pattern("Q", "QQ**Q**QQ");
            allowedPatterns.add(qPattern);
            allowedSymbols.add("Q");
            Pattern xPattern = new Pattern("X", "X*X*X*X*X");
            allowedPatterns.add(xPattern);
            allowedSymbols.add("X");
            Pattern tPattern = new Pattern("T", "TTT**T**T");
            allowedPatterns.add(tPattern);
            allowedSymbols.add("T");
        }
    }


Python:

   def __LoadPuzzle(self, Filename):
       try:
           with open(Filename) as f:
               NoOfSymbols = int(f.readline().rstrip())
               for Count in range (1, NoOfSymbols + 1):
                   self.__AllowedSymbols.append(f.readline().rstrip())
               NoOfPatterns = int(f.readline().rstrip())
               for Count in range(1, NoOfPatterns + 1):
                   Items = f.readline().rstrip().split(",")
                   P = Pattern(Items[0], Items[1])
                   self.__AllowedPatterns.append(P)
               self.__GridSize = int(f.readline().rstrip())
               for Count in range (1, self.__GridSize * self.__GridSize + 1):
                   Items = f.readline().rstrip().split(",")
                   if Items[0] == "@":
                       C = BlockedCell()
                       self.__Grid.append(C)
                   else:
                       C = Cell()
                       C.ChangeSymbolInCell(Items[0])
                       for CurrentSymbol in range(1, len(Items)):
                           C.AddToNotAllowedSymbols(Items[CurrentSymbol])
                       self.__Grid.append(C)
               self.__Score = int(f.readline().rstrip())
               self.__SymbolsLeft = int(f.readline().rstrip())
       except:
           print("Puzzle not loaded")
           Main()
#WikiBooks Q2


VB.NET:

This helps to reset the code so that the program isn't stuck in an infinite loop trying to collect information that cannot be used. Allows the user another chance to re-enter the file name for the puzzle.

        Private Sub LoadPuzzle(Filename As String)
            Try
                Using MyStream As New StreamReader(Filename)
                    Dim NoOfSymbols As Integer = MyStream.ReadLine()
                    For Count = 1 To NoOfSymbols
                        AllowedSymbols.Add(MyStream.ReadLine())
                    Next
                    Dim NoOfPatterns As Integer = MyStream.ReadLine()
                    For Count = 1 To NoOfPatterns
                        Dim Items As List(Of String) = MyStream.ReadLine().Split(",").ToList()
                        Dim P As Pattern = New Pattern(Items(0), Items(1))
                        AllowedPatterns.Add(P)
                    Next
                    GridSize = Convert.ToInt32(MyStream.ReadLine())
                    For Count = 1 To GridSize * GridSize
                        Dim C As Cell
                        Dim Items As List(Of String) = MyStream.ReadLine().Split(",").ToList()
                        If Items(0) = "@" Then
                            C = New BlockedCell()
                        Else
                            C = New Cell()
                            C.ChangeSymbolInCell(Items(0))
                            For CurrentSymbol = 1 To Items.Count - 1
                                C.AddToNotAllowedSymbols(Items(CurrentSymbol))
                            Next
                        End If
                        Grid.Add(C)
                    Next
                    Score = MyStream.ReadLine()
                    SymbolsLeft = MyStream.ReadLine()
                End Using
            Catch
                Console.WriteLine("Puzzle not loaded")
                Call Main() 
            End Try
        End Sub

Alternative approach --> The question asks us to only accept files that exist otherwise play a default game. I have used a function instead as it is more easier to remember.

Main Sub

Sub Main()
    Dim Again As String = "y"
    Dim Score As Integer
    While Again = "y"
        Console.Write("Press Enter to start a standard puzzle or enter name of file to load: ")
        Dim Filename As String = Console.ReadLine()
        Dim MyPuzzle As Puzzle
        If Filename.Length > 0 And isValid(Filename) Then ' added function here
            MyPuzzle = New Puzzle(Filename & ".txt")
        Else
            MyPuzzle = New Puzzle(8, Int(8 * 8 * 0.6))
        End If
        Score = MyPuzzle.AttemptPuzzle()
        Console.WriteLine("Puzzle finished. Your score was: " & Score)
        Console.Write("Do another puzzle? ")
        Again = Console.ReadLine().ToLower()
    End While
    Console.ReadLine()
End Sub

isValid function

Function isValid(path As String) As Boolean
    Try
        If File.Exists(path + ".txt") Then ' adding .txt will cause the code to not read the file
            Dim inp() As String = File.ReadAllLines(path + ".txt") ' reads all input
            If inp.Length > 0 Then ' checks if file is empty
                Return True
            Else
                Console.WriteLine("File is empty.")
                Return False
            End If
        Else
            Console.WriteLine("File does not exist.")
            Return False
        End If
    Catch ex As Exception ' if we experience any exceptions, then we can presume that the file is not a game file
        Console.WriteLine("Error reading file: " & ex.Message)
        Return False
    End Try
End Function


Question 3 - Blow up a block (blocked cell) [10 marks]

edit

Have a 'bomb' that can remove or 'blow-up' a block in a 'blocked cell', but costs you some of your score (minus some points):

C#:

// start change
private string GetSymbolFromUser()
{
    string Symbol = "";
    while (!AllowedSymbols.Contains(Symbol) && Symbol != "bomb")
    {
        Console.Write("Enter symbol or 'bomb' to blow up an @: ");
        Symbol = Console.ReadLine();
    }
    return Symbol;
}
// end change

public virtual int AttemptPuzzle()

// start change
string Symbol = GetSymbolFromUser();
if (Symbol == "bomb" && Score >= 10)
{
    int i = (GridSize - Row) * GridSize + Column  1;
    Grid[i] = new Cell(CurrentCell.GetSymbolsNotAllowed);
    Score -= 10;
}
else if (Symbol == "bomb" && Score < 10)
{
    Console.WriteLine("You do not have sufficient score to use this move");
}
else
{
    SymbolsLeft -= 1;
    Cell CurrentCell = GetCell(Row, Column);
    if (CurrentCell.CheckSymbolAllowed(Symbol))
    {
        CurrentCell.ChangeSymbolInCell(Symbol);
        int AmountToAddToScore = CheckForMatchWithPattern(Row, Column);
        if (AmountToAddToScore > 0)
        {
            Score += AmountToAddToScore;
        }
    }
    if (SymbolsLeft == 0)
    {
        Finished = true;
    }
}
// end change
// start change (in class Cell)
public Cell(List<string> _symbolsNotAllowed)
{
    Symbol = "";
    SymbolsNotAllowed = _symbolsNotAllowed;
}

public List<string> GetSymbolsNotAllowed
{
    get { return SymbolsNotAllowed; }
}
// end change


Delphi/Pascal:


Java:

Adding another symbol B to the list to recognise it in the process.

allowedSymbols.add("B");

And add a condition to the update loop (attemptPuzzle) for the "B" symbol

public int attemptPuzzle() {
        boolean finished = false;
        while (!finished) {
            displayPuzzle();
            Console.writeLine("Current score: " + score);
            int row = -1;
            boolean valid = false;
            while (!valid) {
                Console.write("Enter row number: ");
                try {
                    row = Integer.parseInt(Console.readLine());
                    valid = true;
                } catch (Exception e) {
                }
            }
            int column = -1;
            valid = false;
            while (!valid) {
                Console.write("Enter column number: ");
                try {
                    column = Integer.parseInt(Console.readLine());
                    valid = true;
                } catch (Exception e) {
                }
            }
            String symbol = getSymbolFromUser();
            Cell currentCell = getCell(row, column); // this was moved up for the validation below
            if(symbol.equals("B") && currentCell.getClass() == BlockedCell.class && score > 2) { // check if the symbol is "B", the target is a BlockedCell and the player has enough score to sacrifice
                grid.set((gridSize - row) * gridSize + column - 1, new Cell()); // set an empty cell to the position (indexing can be found in getCell() method)
                score -= 3; // change the score
            } else if (symbol.equals("B")){
                System.out.println("Cannot blow an empty block or you have not enough score to use the command.");
                continue; // start a new iteration BEFORE symbolsLeft is decremented (no move was made)
            }
            symbolsLeft -= 1;
            if (currentCell.checkSymbolAllowed(symbol)) {
                currentCell.changeSymbolInCell(symbol);
                int amountToAddToScore = checkForMatchWithPattern(row, column);
                if (amountToAddToScore > 0) {
                    score += amountToAddToScore;
                }
            }
            if (symbolsLeft == 0) {
                finished = true;
            }
        }
        Console.writeLine();
        displayPuzzle();
        Console.writeLine();
        return score;
    }


Python:

This adds a new symbol "B" which can only be played on a blocked tile.

# Add to the init of Puzzle
self.__AllowedSymbols.append("B")

def AttemptPuzzle(self):
    Finished = False
    while not Finished:
        self.DisplayPuzzle()
        print("Current score: " + str(self.__Score))
        Row = -1
        Valid = False
        while not Valid:
            try:
                Row = int(input("Enter row number: "))
                Valid = True
            except:
                pass
        Column = -1
        Valid = False
        while not Valid:
            try:
                Column = int(input("Enter column number: "))
                Valid = True
            except:
                pass
        Symbol = self.__GetSymbolFromUser()
        self.__SymbolsLeft -= 1
        CurrentCell = self.__GetCell(Row, Column)

        # CHANGES HERE
        if Symbol == "B" and type(CurrentCell) == BlockedCell:
            Index = (self.__GridSize - Row) * self.__GridSize + Column - 1
            self.__Grid[Index] = Cell()  # Change Blocked Cell to regular Cell so the cell is "open"
            self.__Score -= 3

        elif CurrentCell.CheckSymbolAllowed(Symbol) and Symbol != "B":
            CurrentCell.ChangeSymbolInCell(Symbol)
            AmountToAddToScore = self.CheckforMatchWithPattern(Row, Column)
            if AmountToAddToScore > 0:
                self.__Score += AmountToAddToScore

        if self.__SymbolsLeft == 0:
            Finished = True
    print()
    self.DisplayPuzzle()
    print()
    return self.__Score


VB.NET:

      ‘’in Function AttemptPuzzle()            
     '' start change
                Dim Symbol As String = GetSymbolFromUser()
                Dim CurrentCell As Cell = GetCell(Row, Column)
                If ((Symbol = "bomb") And (Score >= 10)) Then
                    Dim i As Integer = ((GridSize - Row) * GridSize + Column) - 1
                    Grid(i) = New Cell
                    Score -= 10
                ElseIf ((Symbol = "bomb") And (Score < 10)) Then
                    Console.WriteLine("You do not have suffiecient score to use this move")

                Else
                    SymbolsLeft -= 1

                    If CurrentCell.CheckSymbolAllowed(Symbol) Then
                        CurrentCell.ChangeSymbolInCell(Symbol)
                        Dim AmountToAddToScore As Integer = CheckForMatchWithPattern(Row, Column)
                        If AmountToAddToScore > 0 Then
                            Score += AmountToAddToScore
                        End If
                    End If
                    If SymbolsLeft = 0 Then
                        Finished = True
                    End If
                End If
                ''end change

Private Function GetSymbolFromUser() As String

    Dim Symbol As String = ""
    ''start change
    While ((Not AllowedSymbols.Contains(Symbol)) And (Not Symbol = "bomb"))
        '' end change
        Console.Write("Enter symbol or 'bomb' to blow up an @: ")
        Symbol = (Console.ReadLine())
    End While

    Return Symbol
End Function


Question 4 - Add additional symbols/letters [3 marks]

edit

Add additional letters/symbols e.g. L or O or U or V or C or H or I.

C#:

The code here will allow you to get 10 points for creating an L shape in the grid.
Pattern LPattern = new Pattern("L", "L***LLLL*");
AllowedPatterns.Add(LPattern);
AllowedSymbols.Add("L");


Delphi/Pascal:


Java:

If you look carefully, you can spot that the pattern recognition goes in a spiral:

0_1_2

7_8_3

6_5_4

So we are going to need to map our new letter the same way:

Example of "L":

L_*_*

L_*_*

L_L_L

Next, simply follow the pattern to create a string:

// ...other patterns
Pattern lPattern = new Pattern("L", "L***LLLL*");
allowedPatterns.add(lPattern);
allowedSymbols.add("L");


Python:

The way that the pattern checking works is in clockwise. This is the order

1 2 3
8 9 4
7 6 5

so the pattern for Q is QQ**Q**QQ, and if you place the symbols in that order, you get the correct pattern.

# Edit Puzzle().init()
class Puzzle():
    def __init__(self, *args):
        LPattern = Pattern("L", "L***LLLL*")
        self.__AllowedPatterns.append(LPattern)
        self.__AllowedSymbols.append("L")


VB.NET:

This allows the user to create an L pattern that results in them earning 10 points.

           Dim LPattern As Pattern = New Pattern("L", "L***LLLL*")
           AllowedPatterns.Add(LPattern)
           AllowedSymbols.Add("L")


Question 5 - Save current game (status) [5 marks]

edit

Save the current status of the game (file-handling)/writing to a text file.

C#:

public virtual int AttemptPuzzle()
{
    bool Finished = false;
    while (!Finished)
    {
        DisplayPuzzle();
        Console.WriteLine("Current score: " + Score);
        bool Valid = false;
        int Row = -1;
        while (!Valid)
        {
            Console.Write("Enter row number: ");
            try
            {
                Row = Convert.ToInt32(Console.ReadLine());
                Valid = true;
            }
            catch
            {
            }
        }
        int Column = -1;
        Valid = false;
        while (!Valid)
        {
            Console.Write("Enter column number: ");
            try
            {
                Column = Convert.ToInt32(Console.ReadLine());
                Valid = true;
            }
            catch
            {
            }
        }
        string Symbol = GetSymbolFromUser();
        SymbolsLeft -= 1
        Cell CurrentCell = GetCell(Row, Column);
        if (CurrentCell.CheckSymbolAllowed(Symbol))
        {
            SymbolsLeft -= 1;
            CurrentCell.ChangeSymbolInCell(Symbol);
            int AmountToAddToScore = CheckForMatchWithPattern(Row, Column);
            if (AmountToAddToScore > 0)
            {
                Score += AmountToAddToScore;
            }
        }
        if (SymbolsLeft == 0)
        {
            Finished = true;
        }
        //New code for question 5 including calling new SavePuzzle() method:
        Console.WriteLine("Do you wish to save your puzzle and exit? (Y for yes)");
        if (Console.ReadLine().ToUpper() == "Y")
        {
            Console.WriteLine("What would you like to save your puzzle as?");
            string file = Console.ReadLine();
            SavePuzzle(file);
            Console.WriteLine("Puzzle Successfully Saved.");
            break;
        }
        //end of code for question 5
    }
    Console.WriteLine();
    DisplayPuzzle();
    Console.WriteLine();
    return Score;

//new SavePuzzle() method:
private void SavePuzzle(string filename)
{
    filename = filename + ".txt";
    using (StreamWriter sw = new StreamWriter(filename))
    {
        sw.WriteLine(AllowedSymbols.Count);
        foreach (var symbol in AllowedSymbols)
        {
            sw.WriteLine(symbol);
        }
        sw.WriteLine(AllowedPatterns.Count);
        foreach (var pattern in AllowedPatterns)
        {
            sw.WriteLine(pattern.GetPatternSymbol() + "," + pattern.GetPatternSequence());
        }
        sw.WriteLine(GridSize);

        foreach (Cell C in Grid)
        {
            List<string> notAllowedSymbol = C.returnNotAllowedSymbols();
            try
            {
                sw.WriteLine(C.GetSymbol() + "," + notAllowedSymbol[0]);
            }
            catch
            {
                sw.WriteLine(C.GetSymbol() + ",");
            }
        }
        sw.WriteLine(Score);
        sw.WriteLine(SymbolsLeft);
    }
}

// new returnNotAllowedSymbol() method in Pattern class 
public virtual List<string> returnNotAllowedSymbols()
{
    return SymbolsNotAllowed;
}


Delphi/Pascal:


Java:

}

   private void savePuzzle(String filename){
       try {
           FileWriter myWriter = new FileWriter(filename);
           myWriter.write(""+allowedSymbols.size()+"\n");
           for (String s:allowedSymbols){
               myWriter.write(s+"\n");
           }
           myWriter.write(""+allowedPatterns.size()+"\n");
           for (Pattern p:allowedPatterns){
               myWriter.write(p.getPatternSequence().charAt(0)+","+p.getPatternSequence()+"\n");
           }
           myWriter.write(""+gridSize+"\n");
           for (Cell c:grid){
             String toWrite=""+c.getSymbol()+",";
             for(String s:allowedSymbols){
                 if (!c.checkSymbolAllowed(s)){
                     toWrite=toWrite+s;
                 }
             }              
             myWriter.write(toWrite+"\n");
           }
           myWriter.write(score+"\n");
           myWriter.write(symbolsLeft+"\n");
           myWriter.close();
       } catch (Exception e) {
           Console.writeLine("Puzzle not saved");
       }
   }
// And changes in attemptPuzzle

           Console.writeLine("Do you wish to save and quit the game y/n?: ");
           String quit = Console.readLine();
           if (quit.equals("y")){
               Console.writeLine("Please enter a filename with a .txt extension: ");
               String fname=Console.readLine();
               savePuzzle(fname);
               finished = true;
           }


Python:

Some of the get methods have to be added manually in each class.

class Puzzle:
    def __save_puzzle(self, filename):
        with open(filename, 'w') as f:
            f.write(f"{len(self.__AllowedSymbols)}\n")
            for i in self.__AllowedSymbols:
                f.write(f"{i}\n")
            f.write(f"{len(self.__AllowedPatterns)}\n")
            for i in self.__AllowedPatterns:
                f.write(f"{i.GetSymbol()},{i.GetPatternSequence()}\n")
            f.write(f"{self.__GridSize}\n")
            for cell in self.__Grid:
                symbol = cell.GetSymbol()
                f.write(f"{symbol if symbol != '-' else ''},{','.join(cell.GetNotAllowedSymbols())}\n")

            f.write(f"{self.__Score}\n")
            f.write(f"{self.__SymbolsLeft}\n")


VB.NET:

Sub SaveGame()

           Console.WriteLine("Enter filename")
           Dim filename As String = Console.ReadLine
           filename = filename & ".txt"
           Dim SR As New StreamWriter(filename)
           'this is the number of symbols
           SR.WriteLine(AllowedSymbols.Count)
           'this loops through the different symbols
           For i As Integer = 0 To AllowedSymbols.Count - 1
               SR.WriteLine(AllowedSymbols(i))
           Next
           'this is the number of patterns
           SR.WriteLine(AllowedPatterns.Count)
           'displays the different patterns
           For j As Integer = 0 To AllowedPatterns.Count - 1
               SR.WriteLine(AllowedSymbols(j) & "," & AllowedPatterns(j).GetPatternSequence)
           Next
           'this is the gridsize
           SR.WriteLine(GridSize)
           'this writes out the grid
           For a As Integer = 0 To Grid.Count - 1
               SR.WriteLine(Grid(a).GetSymbol() & Grid(a).returnNotAllowedList)
           Next
           'this is the current score
           SR.WriteLine(Score)
           'this is the number of symbols left
           SR.WriteLine(SymbolsLeft)
           SR.Close()
       End Sub


'cleaned version (above version has a few issues)

       Public Overridable Function AttemptPuzzle() As Integer
           Dim Finished As Boolean = False
           While Not Finished
               DisplayPuzzle()
               Console.WriteLine("Current score: " & Score)
               Dim Valid As Boolean = False
               Dim Row As Integer = -1
               While Not Valid
                   Console.Write("Enter row number: ")
                   Try
                       Row = Console.ReadLine()
                       Valid = True
                   Catch
                   End Try
               End While
               Dim Column As Integer = -1
               Valid = False
               While Not Valid
                   Console.Write("Enter column number: ")
                   Try
                       Column = Console.ReadLine()
                       Valid = True
                   Catch
                   End Try
               End While
               Dim Symbol As String = GetSymbolFromUser()
               Dim CurrentCell As Cell = GetCell(Row, Column)
               If (Symbol = "bomb") AndAlso (Score >= 10) Then
                   Dim i As Integer = ((GridSize - Row) * GridSize + Column) - 1
                   Grid(i) = New Cell
                   Score -= 10
               ElseIf Symbol = "Bomb" AndAlso Score < 10 Then
                   Console.WriteLine("You do not have sufficient score to use this move")
               Else
                   SymbolsLeft -= 1
                   If CurrentCell.CheckSymbolAllowed(Symbol) Then
                       CurrentCell.ChangeSymbolInCell(Symbol)
                       Dim AmountToAddToScore As Integer = CheckForMatchWithPattern(Row, Column)
                       If AmountToAddToScore > 0 Then
                           Score += AmountToAddToScore
                       End If
                   End If
                   If SymbolsLeft = 0 Then
                       Finished = True
                   End If
                   Console.WriteLine("Would you like to save your puzzle and exit? (Y/N) ")
                   If UCase(Console.ReadLine()) = "Y" Then
                       Console.WriteLine("What name would you like to save your puzzle as ? ")
                       Dim new_filename As String = Console.ReadLine() + ".txt"
                       Dim error_status = SavePuzzle(new_filename)
                       If Not error_status Then
                           Console.WriteLine("Puzzle Successfully Saved. ")
                       End If
                   End If
               End If
           End While
           Console.WriteLine()
           DisplayPuzzle()
           Console.WriteLine()
           Return Score
       End Function
       Private Function SavePuzzle(filename As String) As Boolean
           Dim SR As New StreamWriter(filename)
           SR.WriteLine(AllowedSymbols.Count)
           For i As Integer = 0 To AllowedSymbols.Count - 1
               SR.WriteLine(AllowedSymbols(i))
           Next
           SR.WriteLine(AllowedPatterns.Count)
           For j As Integer = 0 To AllowedPatterns.Count - 1
               SR.WriteLine(AllowedSymbols(j) & "," & AllowedPatterns(j).GetPatternSequence)
           Next
           SR.WriteLine(GridSize)
           For t = 0 To Grid.Count - 1
               Dim notAllowedSymbol As String
               ' Check if returnNotAllowedList is empty
               If Grid(t).returnNotAllowedList.Count > 0 Then
                   notAllowedSymbol = Grid(t).returnNotAllowedList(0)
               Else
                   notAllowedSymbol = ""
               End If
               SR.WriteLine(Grid(t).GetSymbol & "," & notAllowedSymbol)
           Next
           SR.WriteLine(Score)
           SR.WriteLine(SymbolsLeft)
           SR.Close()
           Return True
       End Function

Cell class:

       Public Function returnNotAllowedList() As List(Of String)
           Return SymbolsNotAllowed
       End Function

Alternative approach --> Its better to not modify the Cell class (unless its asked). I have also used string concatenation as its easier to remember during exam stress and is easier to understand/debug.

AttemptPuzzle method

 Public Overridable Function AttemptPuzzle() As Integer
     Dim Finished As Boolean = False
     While Not Finished
         DisplayPuzzle()
         Console.WriteLine("Current score: " & Score)
         Dim Valid As Boolean = False
         Dim Row As Integer = -1
         While Not Valid
             Console.Write("Enter row number: ")
             Try ' CHANGES START FROM HERE
                 Dim inp1 = Console.ReadLine()
                 If (inp1 = "SAVEGAME") Then
                     SaveGame()
                     Valid = False
                 Else
                     Row = Int32.Parse(inp1)
                     Valid = True
                 End If
             Catch ' CHANGE ENDS HERE
             End Try
         End While
         Dim Column As Integer = -1
         Valid = False
         While Not Valid
             Console.Write("Enter column number: ")
             Try ' CHANGES START FROM HERE
                 Dim inp1 = Console.ReadLine()
                 If (inp1 = "SAVEGAME") Then
                     SaveGame()
                     Valid = False
                 Else
                     Column = Int32.Parse(inp1)
                     Valid = True
                 End If
             Catch ' CHANGE ENDS HERE
             End Try
         End While
         Dim Symbol As String = GetSymbolFromUser()
         SymbolsLeft -= 1
         Dim CurrentCell As Cell = GetCell(Row, Column)
         If CurrentCell.CheckSymbolAllowed(Symbol) Then
             CurrentCell.ChangeSymbolInCell(Symbol)
             Dim AmountToAddToScore As Integer = CheckForMatchWithPattern(Row, Column)
             If AmountToAddToScore > 0 Then
                 Score += AmountToAddToScore
             End If
         End If
         If SymbolsLeft = 0 Then
             Finished = True
         End If
     End While
     Console.WriteLine()
     DisplayPuzzle()
     Console.WriteLine()
     Return Score
 End Function

SaveGame method

Private Sub SaveGame()
    Dim alreadyExists As Boolean = True ' start by making your variables
    Dim savePath As String = String.Empty
    Dim fileContent As String = String.Empty
    While alreadyExists ' make a loop until you get valid input
        Console.Write("Enter a name:")
        savePath = Console.ReadLine()
        If File.Exists(savePath + ".txt") Then ' see if it exists
            alreadyExists = True
            Console.WriteLine("Please enter a file name that is not taken already!")
        Else
            alreadyExists = False
        End If
    End While ' We are basically constructing a string that we will then make as a text file, you can StreamReader or StringBuilder but I personally perfer this as its more easier to debug. Use the text files provided and LoadPuzzle method for help
    fileContent = fileContent & (AllowedSymbols.Count.ToString() + Environment.NewLine) ' symbols allowed
    For Each sym In AllowedSymbols
        fileContent = fileContent & (sym + Environment.NewLine) ' add the allowed symbols one by one
    Next
    fileContent = fileContent & (AllowedPatterns.Count.ToString() + Environment.NewLine) ' patterns allowed
    For Each pat In AllowedPatterns
        fileContent = fileContent & (findSymbol(pat.GetPatternSequence().ToString()).ToString() + "," + pat.GetPatternSequence().ToString() + Environment.NewLine) ' Get the Symbol and then the pattern split by ,
    Next
    fileContent = fileContent & (GridSize.ToString() + Environment.NewLine) ' gridsize
    For Each item In Grid ' we export all the cells into the text file
        Dim symbol = item.GetSymbol ' see if its an empty cell or normal/blocked cell
        Dim notAllowed As String = String.Empty
        For Each sym In AllowedSymbols ' checks for the not allowed symbol, would be nice for AQA to make a function for us
            If (Not item.CheckSymbolAllowed(sym)) Then
                notAllowed = sym
                Exit For ' you will get the last symbol if you don't add this
            End If
        Next
        If (symbol = "-") Then ' comma only plus the not allowed symbol
            fileContent = fileContent & ("," + notAllowed.ToString() + Environment.NewLine)
        Else ' the symbol comma plus the not allowed symbol
            fileContent = fileContent & (symbol.ToString() + "," + notAllowed.ToString() + Environment.NewLine)
        End If
    Next
    fileContent = fileContent & (Score.ToString() + Environment.NewLine) ' score
    fileContent = fileContent & (SymbolsLeft.ToString() + Environment.NewLine) ' how many left
    fileContent.TrimEnd() ' bug that creates a random new line is fixed here
    File.WriteAllText(savePath + ".txt", fileContent) ' create txt
End Sub

findSymbol method

Function findSymbol(str As String) ' Not all patterns might start with their symbol, this is a failsafe
    For Each strs In str
        If (strs <> "*") Then
            Return strs
        End If
    Next
End Function


Question 6 - Rotated letter/symbol [9 marks]

edit

Score a 'rotated' symbol/letter (lower score?)

C#:

Rotated letters are given 5 points rather than 10.

 public virtual int CheckForMatchWithPattern(int Row, int Column)
 {
     for (var StartRow = Row + 2; StartRow >= Row; StartRow--)
     {
         for (var StartColumn = Column - 2; StartColumn <= Column; StartColumn++)
         {
             try
             {
                 string PatternString = "";
                 PatternString += GetCell(StartRow, StartColumn).GetSymbol();
                 PatternString += GetCell(StartRow, StartColumn + 1).GetSymbol();
                 PatternString += GetCell(StartRow, StartColumn + 2).GetSymbol();
                 PatternString += GetCell(StartRow - 1, StartColumn + 2).GetSymbol();
                 PatternString += GetCell(StartRow - 2, StartColumn + 2).GetSymbol();
                 PatternString += GetCell(StartRow - 2, StartColumn + 1).GetSymbol();
                 PatternString += GetCell(StartRow - 2, StartColumn).GetSymbol();
                 PatternString += GetCell(StartRow - 1, StartColumn).GetSymbol();
                 PatternString += GetCell(StartRow - 1, StartColumn + 1).GetSymbol();

                 for (int i = 0; i < 4; i++)
                 {
                     foreach (var P in AllowedPatterns)
                     {
                         string CurrentSymbol = GetCell(Row, Column).GetSymbol();
                         if (P.MatchesPattern(PatternString, CurrentSymbol))
                         {
                             GetCell(StartRow, StartColumn).AddToNotAllowedSymbols(CurrentSymbol);
                             GetCell(StartRow, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol);
                             GetCell(StartRow, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol);
                             GetCell(StartRow - 1, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol);
                             GetCell(StartRow - 2, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol);
                             GetCell(StartRow - 2, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol);
                             GetCell(StartRow - 2, StartColumn).AddToNotAllowedSymbols(CurrentSymbol);
                             GetCell(StartRow - 1, StartColumn).AddToNotAllowedSymbols(CurrentSymbol);
                             GetCell(StartRow - 1, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol);
                             
                             if (i == 0)
                             {
                                 return 10;
                             }
                             else
                             {
                                 return 5;
                             }
                         }
                     }

                     PatternString = PatternString.Substring(2, 6) + PatternString.Substring(0, 2) + PatternString[8];
                 }
             }
             catch
             {
             }
         }
     }
     return 0;
 }


Delphi/Pascal:


Java:

public int CheckforMatchWithPattern(int Row, int Column) {
    for (int StartRow = Row + 2; StartRow > Row - 1; StartRow--) {
        for (int StartColumn = Column - 2; StartColumn < Column + 1; StartColumn++) {
            try {
                String PatternString = "";
                PatternString += this.__GetCell(StartRow, StartColumn).GetSymbol();
                PatternString += this.__GetCell(StartRow, StartColumn + 1).GetSymbol();
                PatternString += this.__GetCell(StartRow, StartColumn + 2).GetSymbol();
                PatternString += this.__GetCell(StartRow - 1, StartColumn + 2).GetSymbol();
                PatternString += this.__GetCell(StartRow - 2, StartColumn + 2).GetSymbol();
                PatternString += this.__GetCell(StartRow - 2, StartColumn + 1).GetSymbol();
                PatternString += this.__GetCell(StartRow - 2, StartColumn).GetSymbol();
                PatternString += this.__GetCell(StartRow - 1, StartColumn).GetSymbol();
                PatternString += this.__GetCell(StartRow - 1, StartColumn + 1).GetSymbol();
                String LeftRotation = PatternString.substring(6, 8) + PatternString.substring(0, 6) + PatternString.substring(8);
                String RightRotation = PatternString.substring(2, 7) + PatternString.substring(0, 2) + PatternString.substring(8);
                String DownRotation = PatternString.substring(4, 8) + PatternString.substring(0, 4) + PatternString.substring(8);
                String[] Rotations = {PatternString, LeftRotation, RightRotation, DownRotation};
                for (Pattern P : this.__AllowedPatterns) {
                    for (String rotation : Rotations) {
                        char CurrentSymbol = this.__GetCell(Row, Column).GetSymbol();
                        if (P.MatchesPattern(rotation, CurrentSymbol)) {
                            this.__GetCell(StartRow, StartColumn).AddToNotAllowedSymbols(CurrentSymbol);
                            this.__GetCell(StartRow, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol);
                            this.__GetCell(StartRow, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol);
                            this.__GetCell(StartRow - 1, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol);
                            this.__GetCell(StartRow - 2, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol);
                            this.__GetCell(StartRow - 2, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol);
                            this.__GetCell(StartRow - 2, StartColumn).AddToNotAllowedSymbols(CurrentSymbol);
                            this.__GetCell(StartRow - 1, StartColumn).AddToNotAllowedSymbols(CurrentSymbol);
                            this.__GetCell(StartRow - 1, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol);
                            return 10;
                        }
                    }
                }
            } catch (Exception e) {
                // Handle exception
            }
        }
    }
    return 0;
}


Python:

    def CheckforMatchWithPattern(self, Row, Column):
        for StartRow in range(Row + 2, Row - 1, -1):
            for StartColumn in range(Column - 2, Column + 1):
                try:
                    PatternString = ""
                    PatternString += self.__GetCell(StartRow, StartColumn).GetSymbol()
                    PatternString += self.__GetCell(StartRow, StartColumn + 1).GetSymbol()
                    PatternString += self.__GetCell(StartRow, StartColumn + 2).GetSymbol()
                    PatternString += self.__GetCell(StartRow - 1, StartColumn + 2).GetSymbol()
                    PatternString += self.__GetCell(StartRow - 2, StartColumn + 2).GetSymbol()
                    PatternString += self.__GetCell(StartRow - 2, StartColumn + 1).GetSymbol()
                    PatternString += self.__GetCell(StartRow - 2, StartColumn).GetSymbol()
                    PatternString += self.__GetCell(StartRow - 1, StartColumn).GetSymbol()
                    PatternString += self.__GetCell(StartRow - 1, StartColumn + 1).GetSymbol()
                    LeftRotation = PatternString[6:8] + PatternString[:6]+PatternString[8]
                    RightRotation = PatternString[2:8] + PatternString[0:2] + PatternString[8]
                    DownRotation = PatternString[4:8] + PatternString[:4] + PatternString[8]
                    Rotations = [PatternString, LeftRotation, RightRotation, DownRotation]
                    for P in self.__AllowedPatterns:
                        for rotation in Rotations:
                            CurrentSymbol = self.__GetCell(Row, Column).GetSymbol()
                            if P.MatchesPattern(rotation, CurrentSymbol):
                                self.__GetCell(StartRow, StartColumn).AddToNotAllowedSymbols(CurrentSymbol)
                                self.__GetCell(StartRow, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol)
                                self.__GetCell(StartRow, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol)
                                self.__GetCell(StartRow - 1, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol)
                                self.__GetCell(StartRow - 2, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol)
                                self.__GetCell(StartRow - 2, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol)
                                self.__GetCell(StartRow - 2, StartColumn).AddToNotAllowedSymbols(CurrentSymbol)
                                self.__GetCell(StartRow - 1, StartColumn).AddToNotAllowedSymbols(CurrentSymbol)
                                self.__GetCell(StartRow - 1, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol)
                                return 10
                except:
                    pass
        return 0


VB.NET:

        Public Overridable Function CheckForMatchWithPattern(Row As Integer, Column As Integer) As Integer
            For StartRow = Row + 2 To Row Step -1
                For StartColumn = Column - 2 To Column
                    Try
                        Dim PatternString As String = ""
                        PatternString &= GetCell(StartRow, StartColumn).GetSymbol()
                        PatternString &= GetCell(StartRow, StartColumn + 1).GetSymbol()
                        PatternString &= GetCell(StartRow, StartColumn + 2).GetSymbol()
                        PatternString &= GetCell(StartRow - 1, StartColumn + 2).GetSymbol()
                        PatternString &= GetCell(StartRow - 2, StartColumn + 2).GetSymbol()
                        PatternString &= GetCell(StartRow - 2, StartColumn + 1).GetSymbol()
                        PatternString &= GetCell(StartRow - 2, StartColumn).GetSymbol()
                        PatternString &= GetCell(StartRow - 1, StartColumn).GetSymbol()
                        PatternString &= GetCell(StartRow - 1, StartColumn + 1).GetSymbol()
                        For Each P In AllowedPatterns
                            Dim CurrentSymbol As String = GetCell(Row, Column).GetSymbol()
                            If P.MatchesPattern(PatternString, CurrentSymbol) Then
                                GetCell(StartRow, StartColumn).AddToNotAllowedSymbols(CurrentSymbol)
                                GetCell(StartRow, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol)
                                GetCell(StartRow, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol)
                                GetCell(StartRow - 1, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol)
                                GetCell(StartRow - 2, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol)
                                GetCell(StartRow - 2, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol)
                                GetCell(StartRow - 2, StartColumn).AddToNotAllowedSymbols(CurrentSymbol)
                                GetCell(StartRow - 1, StartColumn).AddToNotAllowedSymbols(CurrentSymbol)
                                GetCell(StartRow - 1, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol)
                                Return 10
                            End If

                            Dim angles = New Integer() {90, 180, 270}
                            For Each i As Integer In angles
                                If P.MatchesPatternRotated(PatternString, CurrentSymbol, i) Then
                                    GetCell(StartRow, StartColumn).AddToNotAllowedSymbols(CurrentSymbol)
                                    GetCell(StartRow, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol)
                                    GetCell(StartRow, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol)
                                    GetCell(StartRow - 1, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol)
                                    GetCell(StartRow - 2, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol)
                                    GetCell(StartRow - 2, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol)
                                    GetCell(StartRow - 2, StartColumn).AddToNotAllowedSymbols(CurrentSymbol)
                                    GetCell(StartRow - 1, StartColumn).AddToNotAllowedSymbols(CurrentSymbol)
                                    GetCell(StartRow - 1, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol)
                                    Return 15
                                End If
                            Next
                        Next
                    Catch
                    End Try
                Next
            Next
            Return 0
        End Function

        Public Function MatchesPatternRotated(PatternString As String, SymbolPlaced As String, Rotation As Integer) As Boolean
            If (SymbolPlaced <> Symbol) Then
                Return False
            End If
            Dim RotatedSequence As String = ""

            Select Case Rotation
                Case 90
                    RotatedSequence = GetPatternSequence().Substring(6, 2) + GetPatternSequence().Substring(0, 6) + GetPatternSequence.Substring(8, 1)
                    'Case 180
                    '... with substring 44 04 81...>
            End Select
            For count = 0 To PatternSequence.Length - 1
                If RotatedSequence(count).ToString() = SymbolPlaced And PatternString(count).ToString() <> Symbol Then
                    Return False
                End If
            Next
            Return True
        End Function


Question 7 - Game difficulty setting [12 marks]

edit

Offer 'game difficulty' setting to change level of game (with greater number of blocked cells)

(Important -> probably lower mark question than 11 makrs, e.g. 4 mark question)

C#:

public Puzzle(int Size, int StartSymbols)
{
    Score = 0;
    SymbolsLeft = StartSymbols;
    GridSize = Size;
    Grid = new List<Cell>();

    // new code for question 5

    int notBlockedChance;
    Console.WriteLine("Would you like the difficulty to be easy (E), medium(M), hard(H) or extremely hard (EH)?");
    string difficulty = Console.ReadLine();
    if (difficulty.ToUpper() == "EH")
    {
        notBlockedChance = 50; //these values are just an example and can be modified
    }
    else if (difficulty.ToUpper() == "H")
    {
        notBlockedChance = 60;
    }
    else if (difficulty.ToUpper() == "M")
    {
        notBlockedChance = 75;
    }
    else
    {
        notBlockedChance = 90;
    }

    for (var Count = 1; Count <= GridSize * GridSize; Count++)
    {
        Cell C;


        if (Rng.Next(1, 101) < notBlockedChance)
        //end of new code for question 5
        {
            C = new Cell();
        }
        else
        {
            C = new BlockedCell();
        }
        Grid.Add(C);
    }
    AllowedPatterns = new List<Pattern>();
    AllowedSymbols = new List<string>();
    Pattern QPattern = new Pattern("Q", "QQ**Q**QQ");
    AllowedPatterns.Add(QPattern);
    AllowedSymbols.Add("Q");
    Pattern XPattern = new Pattern("X", "X*X*X*X*X");
    AllowedPatterns.Add(XPattern);
    AllowedSymbols.Add("X");
    Pattern TPattern = new Pattern("T", "TTT**T**T");
    AllowedPatterns.Add(TPattern);
    AllowedSymbols.Add("T");


}


Delphi/Pascal:


Java:

public class PuzzleSP {
    public static void main(String[] args) {
        String again = "y";
        int score;
        while (again.equals("y")) {
            Console.write("Press Enter to start a standard puzzle or enter name of file to load: ");
            String filename = Console.readLine();
            Puzzle myPuzzle;
            if (filename.length() > 0) {
                myPuzzle = new Puzzle(filename + ".txt");
            } else {
            	
            	//start of altered code
            	
            	Console.writeLine("enter a difficulty (1-3 easy to hard): ");
            	int dif = Integer.parseInt(Console.readLine());
            	if(dif < 1 || dif > 3) {
            		dif = 2;
            	}
                myPuzzle = new Puzzle(8, (int)(8 * 8 * 0.6), dif);
                
                //end of altered code
            }
            score = myPuzzle.attemptPuzzle();
            Console.writeLine("Puzzle finished. Your score was: " + score);
            Console.write("Do another puzzle? ");
            again = Console.readLine().toLowerCase();
        }
        Console.readLine();
    }
}


    public Puzzle(int size, int startSymbols, int difficulty) {  //add difficulty setting
        score = 0;
        symbolsLeft = startSymbols;
        gridSize = size;
        grid = new ArrayList<>();
        for (int count = 1; count < gridSize * gridSize + 1; count++) {
            Cell c;
            int num = 0;
            
            //start of altered code
            
            if(difficulty == 1) {
            	num = 90;
            }
            else if(difficulty == 2) {
            	num = 70;
            }
            else if(difficulty == 3) {
            	num = 50;
            }
            
            //the lower num is, the more difficult the game will be.
            
            if (getRandomInt(1, 101) < num) {
                c = new Cell();
            } else {
                c = new BlockedCell();
            }
            grid.add(c);
            
            //end of altered code            
        }


Python:

class Puzzle():
    def __init__(self, *args):
        if len(args) == 1:
            self.__Score = 0
            self.__SymbolsLeft = 0
            self.__GridSize = 0
            self.__Grid = []
            self.__AllowedPatterns = []
            self.__AllowedSymbols = []
            self.__LoadPuzzle(args[0])
        else:
            self.__Score = 0
            self.__SymbolsLeft = args[1]
            self.__GridSize = args[0]
            self.__Grid = []
            print("1: Easy, 2: Normal, 3: Hard")
            difficulty = ""
            while not (difficulty == "1" or difficulty == "2" or difficulty == "3") or not difficulty.isdigit():
                difficulty = input("Enter a difficulty")
            difficulty = int(difficulty)
            difficulties  = {1:95 , 2:80 , 3:65} #modify these values to change difficulties
            for Count in range(1, self.__GridSize * self.__GridSize + 1):
                if random.randrange(1, 101) < difficulties[difficulty]:
                    C = Cell()
                else:
                    C = BlockedCell()
                self.__Grid.append(C)
            self.__AllowedPatterns = []
            self.__AllowedSymbols = []
            QPattern = Pattern("Q", "QQ**Q**QQ")
            self.__AllowedPatterns.append(QPattern)
            self.__AllowedSymbols.append("Q")
            XPattern = Pattern("X", "X*X*X*X*X")
            self.__AllowedPatterns.append(XPattern)
            self.__AllowedSymbols.append("X")
            TPattern = Pattern("T", "TTT**T**T")
            self.__AllowedPatterns.append(TPattern)
            self.__AllowedSymbols.append("T")

## OR
###Adds ability for users to create new puzzle with custom gridsize and Difficulty ###(increase percentile of grid that is blocked, up to 90%)

def Main():
    Again = "y"
    Score = 0
    while Again == "y":
        Filename = input("Press Enter to start a standard puzzle or enter name of file to load: ")
        if len(Filename) > 0:
            MyPuzzle = Puzzle(Filename + ".txt")
        else:
            GrS = 0
            diff = 0
            while GrS < 3 or GrS > 16:
                GrS = int(input("Input Desired Gridsize (i.e. 5 = 5x5 grid)"))
            while diff <= 0 or diff > 9:
                diff = int(input("Input Desired Difficulty 1-9"))
            diff = diff/10
            diff = 1-diff
            MyPuzzle = Puzzle(GrS, int(GrS * GrS * diff))
        Score = MyPuzzle.AttemptPuzzle()
        print("Puzzle finished. Your score was: " + str(Score))
        Again = input("Do another puzzle? ").lower() # add (y/n)


VB.NET:

Difficulty based on number of moves available

Sub Main()

       Dim Again As String = "y"
       Dim Score As Integer
       While Again = "y"
           Console.Write("Press Enter to start a standard puzzle or enter name of file to load: ")
           Dim Filename As String = Console.ReadLine()
           'ADDED CODE - checks that the filename entered has a file existing in the DEBUG folder
           Dim fileExists As Boolean = False
           Dim FullFilename As String = Filename & ".txt"
           If FileIO.FileSystem.FileExists(FullFilename) Then
               fileExists = True
           End If
           'AMENDED CODE - the if statement changed to use the boolean value above instead of
           'using the text length
           Dim MyPuzzle As Puzzle
           If fileExists Then
               MyPuzzle = New Puzzle(Filename & ".txt")
           Else
               'ADDED CODE
               Dim Dif As Integer
               Do
                   Console.WriteLine("Enter a difficulty rating from 1-9")
                   Dif = Console.ReadLine
               Loop Until Dif >= 1 And Dif < 10
               'AMENDED CODE - difficulty rating affects the numbner of moves available
               MyPuzzle = New Puzzle(8, Int(8 * 8 * (1 - (0.1 * Dif))))
           End If


           Score = MyPuzzle.AttemptPuzzle()
           Console.WriteLine("Puzzle finished. Your score was: " & Score)
           Console.Write("Do another puzzle? ")
           Again = Console.ReadLine().ToLower()
       End While
       Console.ReadLine()
   End Sub
  -> Other Implementation (could be interpreted many ways):
    Class Puzzle
        Private Score As Integer
        Private SymbolsLeft As Integer
        Private GridSize As Integer
        Private Grid As List(Of Cell)
        Private AllowedPatterns As List(Of Pattern)
        Private AllowedSymbols As List(Of String)

        Sub New(Filename As String)
            Grid = New List(Of Cell)
            AllowedPatterns = New List(Of Pattern)
            AllowedSymbols = New List(Of String)
            LoadPuzzle(Filename)
        End Sub

        Sub New(Size As Integer, StartSymbols As Integer)
            Score = 0
            SymbolsLeft = StartSymbols
            GridSize = Size
            Grid = New List(Of Cell)

            'START CHANGE HERE
            Dim difficulty As Integer = -1
            While difficulty < 1 OrElse difficulty > 9
                Console.WriteLine("Enter a difficulty rating from 1-9")
                difficulty = Console.ReadLine()
            End While

            For Count = 1 To GridSize * GridSize
                Dim C As Cell
                If Rng.Next(1, 101) < (10 * (10 - difficulty)) Then
                    C = New Cell()
                Else
                    C = New BlockedCell()
                End If
                Grid.Add(C)
            Next
            'STOP CHANGE HERE

            AllowedPatterns = New List(Of Pattern)
            AllowedSymbols = New List(Of String)
            Dim QPattern As Pattern = New Pattern("Q", "QQ**Q**QQ")
            AllowedPatterns.Add(QPattern)
            AllowedSymbols.Add("Q")
            Dim XPattern As Pattern = New Pattern("X", "X*X*X*X*X")
            AllowedPatterns.Add(XPattern)
            AllowedSymbols.Add("X")
            Dim TPattern As Pattern = New Pattern("T", "TTT**T**T")
            AllowedPatterns.Add(TPattern)
            AllowedSymbols.Add("T")
        End Sub


Question 8 - Fix symbols placed error [9 marks]

edit

When you try place a symbol in a invalid cell it still counts as a placed cell towards the amount of symbols placed.

C#:

public virtual int AttemptPuzzle()
{
    bool Finished = false;
    while (!Finished)
    {
        DisplayPuzzle();
        Console.WriteLine("Current score: " + Score);
        bool Valid = false;
        int Row = -1;
        while (!Valid)
        {
            Console.Write("Enter row number: ");
            try
            {
                Row = Convert.ToInt32(Console.ReadLine());
                Valid = true;
            }
            catch
            {
            }
        }
        int Column = -1;
        Valid = false;
        while (!Valid)
        {
            Console.Write("Enter column number: ");
            try
            {
                Column = Convert.ToInt32(Console.ReadLine());
                Valid = true;
            }
            catch
            {
            }
        }
        string Symbol = GetSymbolFromUser();
        //SymbolsLeft -= 1; => moved inside the IF statement
        Cell CurrentCell = GetCell(Row, Column);
        if (CurrentCell.CheckSymbolAllowed(Symbol))
        {
            SymbolsLeft -= 1; //moved inside if statement to fix error
            CurrentCell.ChangeSymbolInCell(Symbol);
            int AmountToAddToScore = CheckForMatchWithPattern(Row, Column);
            if (AmountToAddToScore > 0)
            {
                Score += AmountToAddToScore;
            }
        }
        if (SymbolsLeft == 0)
        {
            Finished = true;
        }

    }
    Console.WriteLine();
    DisplayPuzzle();
    Console.WriteLine();
    return Score;
}


Delphi/Pascal:


Java:


Python:

    def AttemptPuzzle(self):
        Finished = False
        while not Finished:
            self.DisplayPuzzle()
            print("Current score: " + str(self.__Score))
            Row = -1
            Valid = False
            while not Valid:
                try:
                    Row = int(input("Enter row number: "))
                    Valid = True
                except:
                    pass
            Column = -1
            Valid = False
            while not Valid:
                try:
                    Column = int(input("Enter column number: "))
                    Valid = True
                except:
                    pass
            Symbol = self.__GetSymbolFromUser()
            # self.__SymbolsLeft -= 1 moving this line inside of the if statement
            CurrentCell = self.__GetCell(Row, Column)
            if CurrentCell.CheckSymbolAllowed(Symbol) and CurrentCell.IsEmpty()  == True: # added to make sure that the cell is empty as well before adding to that cell 
                self.__SymbolsLeft -= 1 # moved into the if statement
                CurrentCell.ChangeSymbolInCell(Symbol)
                AmountToAddToScore = self.CheckforMatchWithPattern(Row, Column)
                if AmountToAddToScore > 0:
                    self.__Score += AmountToAddToScore
            if self.__SymbolsLeft == 0:
                Finished = True
        print()
        self.DisplayPuzzle()
        print()
        return self.__Score


VB.NET:

          Public Overridable Function AttemptPuzzle() As Integer
            Dim Finished As Boolean = False
            While Not Finished
                DisplayPuzzle()
                Console.WriteLine("Current score: " & Score)
                Dim Valid As Boolean = False
                Dim Row As Integer = -1
                While Not Valid
                    Console.Write("Enter row number: ")
                    Try
                        Row = Console.ReadLine()
                        Valid = True
                    Catch
                    End Try
                End While
                Dim Column As Integer = -1
                Valid = False
                While Not Valid
                    Console.Write("Enter column number: ")
                    Try
                        Column = Console.ReadLine()
                        Valid = True
                    Catch
                    End Try
                End While
                Dim Symbol As String = GetSymbolFromUser()
                'START CHANGE
                'SymbolsLeft -= 1 -> moved from this old place
                Dim CurrentCell As Cell = GetCell(Row, Column)
                If CurrentCell.CheckSymbolAllowed(Symbol) Then
                    SymbolsLeft -= 1 'to here, inside the if statement to only substract ammount of symbol left if it was not placed on a blocked cell
                    CurrentCell.ChangeSymbolInCell(Symbol)
                    Dim AmountToAddToScore As Integer = CheckForMatchWithPattern(Row, Column)
                    If AmountToAddToScore > 0 Then
                        Score += AmountToAddToScore
                    End If
                End If
                'END CHANGE
                If SymbolsLeft = 0 Then
                    Finished = True
                End If
            End While
            Console.WriteLine()
            DisplayPuzzle()
            Console.WriteLine()
            Return Score
        End Function


Question 9 - Create a new puzzle file to be imported [5 marks]

edit

Create a new puzzle file to be imported into the code for the user to play:

C#:

## annotated puzzle file, so parameters can be altered as needed

4  #number of accepted symbols
Q  
T
X
O  #new symbols can be added here, like so
4  #number of accepted patterns
Q,QQ**Q**QQ
X,X*X*X*X*X
T,TTT**T**T
O,OOOOOOOO*   #new patterns can be added here (in proper format), like so
5  #grid size (if size = x, grid is x by x). number of entries (below) should match grid size (5 * 5 = 25 in this case)
Q,Q   #First symbol is symbol on board, second symbol is symbols not allowed on that grid
Q,Q
@,Q
,
,
Q,Q
Q,Q
,Q  #eg denotes an empty space, but symbol Q is not allowed
,
,
,
X,Q
Q,Q
X,
,
,
,
X,
,
,
,
X,
,
,
,
10  #starting score
1   #number of moves


Delphi/Pascal:


Java:


Python:

## annotated puzzle file, so parameters can be altered as needed

4  #number of accepted symbols
Q  
T
X
O  #new symbols can be added here, like so
4  #number of accepted patterns
Q,QQ**Q**QQ
X,X*X*X*X*X
T,TTT**T**T
O,OOOOOOOO*   #new patterns can be added here (in proper format), like so
5  #grid size (if size = x, grid is x by x). number of entries (below) should match grid size (5 * 5 = 25 in this case)
Q,Q   #First symbol is symbol on board, second symbol is symbols not allowed on that grid
Q,Q
@,Q
,
,
Q,Q
Q,Q
,Q  #eg denotes an empty space, but symbol Q is not allowed
,
,
,
X,Q
Q,Q
X,
,
,
,
X,
,
,
,
X,
,
,
,
10  #starting score
1   #number of moves


VB.NET:


Question 10 - Be able to undo a move [10 marks]

edit

Alter the attemptPuzzle subroutine such that the user is asked if they wish to undo their last move prior to the place in the loop where there is a check for symbolsLeft being equal to zero. Warn them that this will lose them 3 points.

If the player chooses to undo:

a.      revert the grid back to its original state

b.      ensure symbolsLeft has the correct value

c.      ensure score reverts to its original value minus the 3 point undo penalty

d. ensure any changes made to a cell’s symbolsNotAllowed list are undone as required

C#:

        while (!Valid)
        {
            Console.Write("Enter column number: ");
            try
            {
                Column = Convert.ToInt32(Console.ReadLine());
                Valid = true;
            }
            catch
            {
            }
        }
        string Symbol = GetSymbolFromUser();
        SymbolsLeft -= 1;

        // change - required in case we need to undo
        int previousScore = Score;

        // this is where the game is updated
        Cell CurrentCell = GetCell(Row, Column);
        if (CurrentCell.CheckSymbolAllowed(Symbol))
        {
            CurrentCell.ChangeSymbolInCell(Symbol);
            int AmountToAddToScore = CheckForMatchWithPattern(Row, Column);
            if (AmountToAddToScore > 0)
            {
                Score += AmountToAddToScore;
            }
        }

        // changed code in AttemptPuzzle here
        DisplayPuzzle();
        Console.WriteLine("Current score: " + Score);

        Console.Write("Do you want to undo (cost 3 points)? y/n: ");
        string answer = Console.ReadLine();

        if (answer == "y" || answer == "Y")
        {
            // undo
            Cell currentCell = GetCell(Row, Column);
            currentCell.RemoveSymbol(Symbol);
            Score = previousScore - 3;
            SymbolsLeft += 1;
        }
        // end change

        if (SymbolsLeft == 0)
        {
            Finished = true;
        }



    }
    Console.WriteLine();
    DisplayPuzzle();
    Console.WriteLine();


    return Score;
}

// added to cell class so that the symbol can be removed if an
// undo is required
public virtual void RemoveSymbol(string SymbolToRemove)
{
    Symbol = "";
    SymbolsNotAllowed.Remove(SymbolToRemove);
}


Delphi/Pascal:


Java:

//Add two atributes in puzzle to store the start position of the last pattern matched
class Puzzle {

    private int score;
    private int symbolsLeft;
    private int gridSize;
    private List<Cell> grid;
    private List<Pattern> allowedPatterns;
    private List<String> allowedSymbols;
    private static Random rng = new Random();

    private int patternStartRow;
    private int patternStartColumn;

// Add a subroutine to the cell class to allow removal from the notAllowedSymbol list

    public void removeLastNotAllowedSymbols() {
        int size = symbolsNotAllowed.size();
        if (size > 0) {
            symbolsNotAllowed.remove(size - 1);
        }
    }

// Alter checkForMatchWithPattern to store the start row and column of any successfully matched pattern
//...

  if (p.matchesPattern(patternString, currentSymbol)) {
           patternStartRow = startRow;
           patternStartColumn = startColumn;
//...etc

//The altered attemptPuzzle subroutine
    public int attemptPuzzle() {
        boolean finished = false;
        while (!finished) {
            displayPuzzle();
            Console.writeLine("Current score: " + score);
            int row = -1;
            boolean valid = false;
            while (!valid) {
                Console.write("Enter row number: ");
                try {
                    row = Integer.parseInt(Console.readLine());
                    valid = true;
                } catch (Exception e) {
                }
            }
            int column = -1;
            valid = false;
            while (!valid) {
                Console.write("Enter column number: ");
                try {
                    column = Integer.parseInt(Console.readLine());
                    valid = true;
                } catch (Exception e) {
                }
            }

            //Set up variables to store the current game state in
            // case of an UNDO
            int undoScore = score;
            int undoSymbolsLeft = symbolsLeft;
            String undoSymbol = getCell(row, column).getSymbol();

            String symbol = getSymbolFromUser();
            symbolsLeft -= 1;
            Cell currentCell = getCell(row, column);
            if (currentCell.checkSymbolAllowed(symbol)) {
                currentCell.changeSymbolInCell(symbol);
                int amountToAddToScore = checkForMatchWithPattern(row, column);
                if (amountToAddToScore > 0) {
                    score += amountToAddToScore;
                }
            }

            //Prompt the user if they wish to undo
            Console.println(" Do you wish to undo your last move? It will cost you 3 points (y/n): ");
            String choice = Console.readLine();
            if (choice.equals("y")) {
                if (score != undoScore) { //A pattern has been matched
                    //The symbolsNotAllowed list may have changed for some cells - the current symbol needs 
                    //                              removing from the end of each list
                    getCell(patternStartRow, patternStartColumn).removeLastNotAllowedSymbols();
                    getCell(patternStartRow, patternStartColumn + 1).removeLastNotAllowedSymbols();
                    getCell(patternStartRow, patternStartColumn + 2).removeLastNotAllowedSymbols();
                    getCell(patternStartRow - 1, patternStartColumn + 2).removeLastNotAllowedSymbols();
                    getCell(patternStartRow - 2, patternStartColumn + 2).removeLastNotAllowedSymbols();
                    getCell(patternStartRow - 2, patternStartColumn + 1).removeLastNotAllowedSymbols();
                    getCell(patternStartRow - 2, patternStartColumn).removeLastNotAllowedSymbols();
                    getCell(patternStartRow - 1, patternStartColumn).removeLastNotAllowedSymbols();
                    getCell(patternStartRow - 1, patternStartColumn + 1).removeLastNotAllowedSymbols();
                }
                score = undoScore - 3;
                symbolsLeft = undoSymbolsLeft;
                currentCell.changeSymbolInCell(undoSymbol);
            }

            if (symbolsLeft == 0) {
                finished = true;
            }
        }
        Console.writeLine();
        displayPuzzle();
        Console.writeLine();
        return score;
    }


Python:

    def AttemptPuzzle(self):
        Finished = False
        while not Finished:
            self.DisplayPuzzle()
            print("Current score: " + str(self.__Score))
            Row = -1
            Valid = False
            while not Valid:
                try:
                    Row = int(input("Enter row number: "))
                    if Row in range(1, self.__GridSize+1):
                        Valid = True
                except:
                    pass
            Column = -1
            Valid = False
            while not Valid:
                try:
                    Column = int(input("Enter column number: "))
                    if Column in range(1, self.__GridSize+1):
                        Valid = True
                except:
                    pass

            # CHANGES START HERE
            Symbol = self.__GetSymbolFromUser()
            undo_symbolsleft = self.__SymbolsLeft
            self.__SymbolsLeft -= 1
            CurrentCell = self.__GetCell(Row, Column)
            undo_cellsymbol = CurrentCell.GetSymbol()
            undo_score = self.__Score
            if CurrentCell.CheckSymbolAllowed(Symbol):
                CurrentCell.ChangeSymbolInCell(Symbol)
                AmountToAddToScore = self.CheckforMatchWithPattern(Row, Column)
                if AmountToAddToScore > 0:
                    self.__Score += AmountToAddToScore

            undo = input('Would you like to undo your move? You will lose 3 points. Y/N: ')
            if undo.upper() == 'Y':
                self.__Score = undo_score - 3
                self.__SymbolsLeft = undo_symbolsleft
                CurrentCell.ChangeSymbolInCell(undo_cellsymbol)
            # CHANGES END HERE

            if self.__SymbolsLeft == 0:
                Finished = True
        print()
        self.DisplayPuzzle()
        print()
        return self.__Score
    def AttemptPuzzle(self):
        Finished = False
        while not Finished:
            self.DisplayPuzzle()
            print("Current score: " + str(self.__Score))
            Row = -1
            Valid = False
            while not Valid:
                try:
                    Row = int(input("Enter row number: "))
                    Valid = True
                except:
                    pass
            Column = -1
            Valid = False
            while not Valid:
                try:
                    Column = int(input("Enter column number: "))
                    Valid = True
                except:
                    pass
            Symbol = self.__GetSymbolFromUser()
            CurrentCell = self.__GetCell(Row, Column)
            UndoList = self.SaveForUndo(Symbol, CurrentCell, Row, Column) # Changed
            if CurrentCell.CheckSymbolAllowed(Symbol):
                self.__SymbolsLeft -= 1 # Changed
                CurrentCell.ChangeSymbolInCell(Symbol)
                AmountToAddToScore = self.CheckforMatchWithPattern(Row, Column)
                if AmountToAddToScore > 0:
                    self.__Score += AmountToAddToScore
            print() # Changed
            self.DisplayPuzzle() # Changed
            print() # Changed
            Choice = input("Would you like to undo last move? (Y/N) ").lower() # Changed
            if Choice.lower() == "y": # Changed
                self.__SymbolsLeft = int(UndoList[0]) # Changed
                CurrentCell._Symbol = UndoList[2] # Changed
                self.__Score = int(UndoList[3]) - 3 # Changed
                for n in range(0, (len(self.__Grid)-1)): # Changed
                    if UndoList[1] in self.__Grid[n]._Cell__SymbolsNotAllowed: # Changed
                        self.__Grid[n].RemoveFromNotAllowedSymbols(UndoList[1]) # Changed
            if self.__SymbolsLeft == 0:
                Finished = True

#Added methods used in edited AttemptPuzzle

def SaveForUndo(self,Symbol, Cell, Row, Column):
        List = []
        List.append(str(self.__SymbolsLeft))
        List.append(str(Symbol))
        List.append(str(Cell._Symbol))
        List.append(str(self.__Score))
        for n in range(0, len(self.__Grid)):
            List.append(self.__Grid[n]._Cell__SymbolsNotAllowed)
        return List

def RemoveFromNotAllowedSymbols(self, SymbolToRemove):
    self.__SymbolsNotAllowed.remove(SymbolToRemove)


VB.NET:

          Public Overridable Function AttemptPuzzle() As Integer
            Dim Finished As Boolean = False
            Dim CurrentCell As Cell
            Dim Symbol As String
            Dim previous_score As Integer
            While Not Finished
                DisplayPuzzle()
                Console.WriteLine("Current score: " & Score)
                Dim Valid As Boolean = False
                Dim Row As Integer = -1
                While Not Valid
                    Console.Write("Enter row number: ")
                    Try
                        Row = Console.ReadLine()
                        Valid = True
                    Catch
                    End Try
                End While
                Dim Column As Integer = -1
                Valid = False
                While Not Valid
                    Console.Write("Enter column number: ")
                    Try
                        Column = Console.ReadLine()
                        Valid = True
                    Catch
                    End Try
                End While
                Symbol = GetSymbolFromUser()
                SymbolsLeft -= 1

                'FIRST CHANGE HERE
                previous_score = Score

                CurrentCell = GetCell(Row, Column)
                If CurrentCell.CheckSymbolAllowed(Symbol) Then
                    CurrentCell.ChangeSymbolInCell(Symbol)
                    Dim AmountToAddToScore As Integer = CheckForMatchWithPattern(Row, Column)
                    If AmountToAddToScore > 0 Then
                        Score += AmountToAddToScore
                    End If
                End If

                'SECOND CHANGE HERE
                If previous_score >= 3 Then
                    Console.WriteLine("Current score: " & Score)
                    Console.WriteLine()
                    DisplayPuzzle()
                    Console.WriteLine()
                    Console.WriteLine("Do you want to undo the last change (cost 3 points)? (Y/N) ")
                    Dim answer_input As Char = UCase(Console.ReadLine())
                    If answer_input = "Y" Then
                        CurrentCell.RemoveSymbol(Symbol)
                        Score = previous_score - 3
                        SymbolsLeft += 1
                    End If
                End If
                'UNTIL HERE

                If SymbolsLeft = 0 Then
                    Finished = True
                End If
            End While
            Console.WriteLine()
            DisplayPuzzle()
            Console.WriteLine()


            Return Score
        End Function

    Class Cell
        Protected Symbol As String
        Private SymbolsNotAllowed As List(Of String)

        Sub New()
            Symbol = ""
            SymbolsNotAllowed = New List(Of String)
        End Sub

        'LAST CHANGE HERE
        Public Sub RemoveSymbol(Symbol_to_remove As String)
            Symbol = ""
            SymbolsNotAllowed.Remove(Symbol_to_remove)
        End Sub
        ' END OF CHANGE

...


Question 11- Validation of Row and Column entries [5 marks]

edit

Description of problem: Validate row and column number entries to only allow numbers within the grid size.

C#:

public virtual int AttemptPuzzle()
{
    bool Finished = false;
    while (!Finished)
    {
        DisplayPuzzle();
        Console.WriteLine("Current score: " + Score);
        bool Valid = false;
        int Row = -1;
        while (!Valid)
        {
            Console.Write("Enter row number: ");
            try
            {
                Row = Convert.ToInt32(Console.ReadLine());
                // change to validate row
                if (Row > 0 && Row <= GridSize)
                {
                    Valid = true;
                }
            }
            catch
            {
            }
        }
        int Column = -1;
        Valid = false;
        while (!Valid)
        {
            Console.Write("Enter column number: ");
            try
            {
                Column = Convert.ToInt32(Console.ReadLine());
                // validate column
                if (Column > 0 && Column <= GridSize)
                {
                    Valid = true;
                }

            }
            catch
            {
            }
        }


Delphi/Pascal:


Java:

    public int attemptPuzzle() {
        boolean finished = false;
        while (!finished) {
            displayPuzzle();
            Console.writeLine("Current score: " + score);
            int row = -1;
            boolean valid = false;
            while (!valid) {
                Console.write("Enter row number: ");
                try {
                    row = Integer.parseInt(Console.readLine());
                    if(row>=1&&row<=gridSize){ //new check
                        valid = true; 
                    }
                } catch (Exception e) {
                }
            }
            int column = -1;
            valid = false;
            while (!valid) {
                Console.write("Enter column number: ");
                try {
                    column = Integer.parseInt(Console.readLine());
                    if (column>=1&&column<=gridSize){ //new check
                        valid = true;
                    }
                } catch (Exception e) {
                }
            }
            String symbol = getSymbolFromUser();
            symbolsLeft -= 1;
//etc....


Python:

def AttemptPuzzle(self):
        Finished = False
        while not Finished:
            self.DisplayPuzzle()
            print("Current score: " + str(self.__Score))
            Row = -1
            Valid = False
            while not Valid:
                Row = int(input("Enter row number: "))
                if Row > self.__GridSize or Row <= 0:
                    print("Invalid Row number\nPlease try again\n")
                    continue
                else:
                    Valid = True
            Column = -1
            Valid = False
            while not Valid:
                Column = int(input("Enter column number: "))
                if Column > self.__GridSize or Column <= 0:
                    print("Invalid Column number\nPlease try again\n")
                    continue
                else:
                    Valid = True
            Symbol = self.__GetSymbolFromUser()
            self.__SymbolsLeft -= 1
            CurrentCell = self.__GetCell(Row, Column)
            if CurrentCell.CheckSymbolAllowed(Symbol):
                CurrentCell.ChangeSymbolInCell(Symbol)
                AmountToAddToScore = self.CheckforMatchWithPattern(Row, Column)
                if AmountToAddToScore > 0:
                    self.__Score += AmountToAddToScore
            if self.__SymbolsLeft == 0:
                Finished = True
        print()
        self.DisplayPuzzle()
        print()
        return self.__Score


VB.NET:

          Public Overridable Function AttemptPuzzle() As Integer
            Dim Finished As Boolean = False
            While Not Finished
                DisplayPuzzle()
                Console.WriteLine("Current score: " & Score)
                Dim Valid As Boolean = False
                Dim Row As Integer = -1
                While Not Valid
                    Console.Write("Enter row number: ")
                    'CHANGE HERE
                    Try
                        Row = Console.ReadLine()
                        If Row > 0 AndAlso Row <= GridSize Then
                            Valid = True
                        End If
                    Catch
                        'END CHANGE
                    End Try
                End While
                Dim Column As Integer = -1
                Valid = False
                While Not Valid
                    Console.Write("Enter column number: ")
                    'CHANGE HERE
                    Try
                        Column = Console.ReadLine()
                        If Column > 0 AndAlso Column <= GridSize Then
                            Valid = True
                        End If
                    Catch
                        'END CHANGE
                    End Try
                End While
                Dim Symbol As String = GetSymbolFromUser()
                SymbolsLeft -= 1
                Dim CurrentCell As Cell = GetCell(Row, Column)
                If CurrentCell.CheckSymbolAllowed(Symbol) Then
                    CurrentCell.ChangeSymbolInCell(Symbol)
                    Dim AmountToAddToScore As Integer = CheckForMatchWithPattern(Row, Column)
                    If AmountToAddToScore > 0 Then
                        Score += AmountToAddToScore
                    End If
                End If
                If SymbolsLeft = 0 Then
                    Finished = True
                End If
            End While
            Console.WriteLine()
            DisplayPuzzle()
            Console.WriteLine()
            Return Score
        End Function

Question 12 - Why is UpdateCell() empty and never called?

edit

Description of problem: Currently, the UpdateCell() method contains 'pass' and is not called anywhere in the program. This will almost certainly be a question, otherwise why would they include it? This may relate to the bombing idea where a Blocked Cell is bombed, and the UpdateCell() is then called to modify this Blocked Cell into a normal cell. Please suggest other ideas of what this method could be used for. Its probably used for changing a blocked cell in a pattern to a normal cell to complete a pattern.


UpdateCell() could be used for unlocking a 3*3 grid if a pattern is broken allowing you to replace the symbol. This would also need to decrease the score after the pattern is broken.

C#:

There are no logical errors with GetCell() as the following extract will prove

public virtual int AttemptPuzzle()
{
    bool Finished = false;
    while (!Finished)
    {
        DisplayPuzzle();

        // row
        for (int row = 8; row >= 1; row--)
        {
            for (int col = 1; col <= 8; col++)
            {
                Cell cell = GetCell(row, col);
                Console.Write(cell.GetSymbol() + " : ");
            }
            Console.Write(Environment.NewLine);
        }
However, if row and column values beyond that of the grid are entered, errors will occur. See solution for Question 12 to solve this issue.


Delphi/Pascal:


Java:


Python:


VB.NET:


Question 13 - Implement a wildcard *

edit

Implement a special character * which is a wildcard. The wildcard can be used to represent any character so that multiple matches can be made with the same cell. Give the player 3 wildcards in random positions at the start of the game.

a) Alter the standard Puzzle constructor (not the load game one) to call ChangeSymbolInCell for 3 random cells, passing in * as the new symbol. Note that blocked cells cannot be changed to wildcard ones so you need to add code to ensure the randomly selected cell is not a blocked cell.

b) In class Cell alter the method. ChangeSymbolInCell such that wildcard cells will never have their symbol changed from * once set. In the same class, alter method CheckSymbolAllowed such that wildcard cells always return true.

c) Alter method MatchesPattern in class Pattern to allow correct operation for the new wildcard *

d) Test that a wildcard can successfully match within two different patterns

C#:

class Puzzle
{
    // add property to Puzzle to give 3 wildcards
    private int NumWildcards = 3;


// ensure GetSymbolFromUser will accept wildcard
private string GetSymbolFromUser()
{
    string Symbol = "";
    // take into account the wildcard symbol
    while (!AllowedSymbols.Contains(Symbol) && Symbol != "*" && NumWildcards > 0)
    {
        Console.Write("Enter symbol: ");
        Symbol = Console.ReadLine();
    }

    // only allow three wildcards
    if (Symbol == "*")
    {
        NumWildcards--;
    }

    return Symbol;
}

// modify Matches Pattern
public virtual bool MatchesPattern(string PatternString, string SymbolPlaced)
{
    // ensure that wildcards are taken into account
    if (SymbolPlaced != Symbol && SymbolPlaced != "*")
    {
        return false;
    }
    for (var Count = 0; Count < PatternSequence.Length; Count++)
    {
        // ignore wildcard symbols as these all count
        if (PatternString[Count] == '*')
        {
            continue;
        }

        if (PatternSequence[Count].ToString() == Symbol && PatternString[Count].ToString() != Symbol)
        {
            return false;
        }
    }
    return true;
}


Delphi/Pascal:


Java:

//after the grid is initialised in puzzle:
        int gridLength = grid.size();
        for (int i=0;i<3;i++){
            //Get random cell
            int randcell = getRandomInt(0,gridLength-1);
            if (!grid.get(randcell).getSymbol().equals("@")){
                grid.get(randcell).changeSymbolInCell("*");
            }            
        }

// From Cell class: 
 public void changeSymbolInCell(String newSymbol) {
        if (!symbol.equals("*")){
            symbol = newSymbol;
        }
   }

 public boolean checkSymbolAllowed(String symbolToCheck) {
        if (!symbol.equals("*")){
            for (String item : symbolsNotAllowed) {
                if (item.equals(symbolToCheck)) {
                return false;
                }
            }
        }
        return true;                
    }

   //Pattern class

public boolean matchesPattern(String patternString, String symbolPlaced) {
        Console.println("This pattern sequence: "+patternSequence+ "Passed in PatternString: "+patternString+ "Symbol:"+ symbolPlaced);
        if (!symbolPlaced.equals(symbol)) {
            return false;
        } else {
            for (int count = 0; count < patternSequence.length(); count++) {
                if (patternSequence.charAt(count) == symbol.charAt(0) && patternString.charAt(count) != symbol.charAt(0)) {
                    if (patternString.charAt(count)!='*'){ //only return false if not a wildcard
                        return false;
                    }
                }
            }
        }
        return true;
    }


Python:

Change no. 1:

while self.__wildcards_left > 0:

   SymbolGridCheck = self.__Grid[random.randint(0, len(self.__Grid))]
   if SymbolGridCheck.GetSymbol() != "W":
       SymbolGridCheck.ChangeSymbolInCell("W")
       self.__wildcards_left -= 1

Change no. 2:

def MatchesPattern(self, PatternString, SymbolPlaced):

       if self.__Symbol == "W":
           ...
       elif SymbolPlaced != self.__Symbol:
           return False
       for Count in range(0, len(self.__PatternSequence)):
           try:
               if self.__PatternSequence[Count] == self.__Symbol and PatternString[Count] == "W":
                   ...
               elif self.__PatternSequence[Count] == self.__Symbol and PatternString[Count] != self.__Symbol:
                   return False
           except Exception as ex:
               print(f"EXCEPTION in MatchesPattern: {ex}")
       return True

Change no. 3:

def ChangeSymbolInCell(self, NewSymbol):

       if self._Symbol == "W":
           ...
       else:
           self._Symbol = NewSymbol

def CheckSymbolAllowed(self, SymbolToCheck):

       for Item in self.__SymbolsNotAllowed:
           if Item == "W":
               ...
           elif Item == SymbolToCheck:
               return False
       return True
by Sami Albizreh


VB.NET:


Question 14 - Program allows the user to replace already placed symbols [9 marks]

edit

the user can replace already placed symbols, and patterns, and not lose points (can fix either by stopping them replacing, or make them lose the points from the pattern the replaced):

C#:


Delphi/Pascal:


Java:


Python:

    def AttemptPuzzle(self):
        Finished = False
        while not Finished:
            self.DisplayPuzzle()
            print("Current score: " + str(self.__Score))
            Row = -1
            Valid = False
            while not Valid:
                try:
                    Row = int(input("Enter row number: "))
                    Valid = True
                except:
                    pass
            Column = -1
            Valid = False
            while not Valid:
                try:
                    Column = int(input("Enter column number: "))
                    Valid = True
                except:
                    pass
            Symbol = self.__GetSymbolFromUser()
            self.__SymbolsLeft -= 1
            CurrentCell = self.__GetCell(Row, Column)
            if CurrentCell.CheckSymbolAllowed(Symbol) and CurrentCell.GetSymbol() == "-": #And added to check that the cell is empty so that cells cannot be placed on top of each other
                CurrentCell.ChangeSymbolInCell(Symbol)
                AmountToAddToScore = self.CheckforMatchWithPattern(Row, Column)
                if AmountToAddToScore > 0:
                    self.__Score += AmountToAddToScore
            if self.__SymbolsLeft == 0:
                Finished = True
        print()
        self.DisplayPuzzle()
        print()
        return self.__Score


VB.NET:


Question 15 - Program allows the user to create their own patterns and symbols [6 marks]

edit

Description of problem:

1) request the user to create their own symbols

2) request the pattern associated with the symbol

3) output an empty grid for the user, so the user can input any coordinates to create their own pattern

4) make sure new symbols and pattern can be verified by the program

EDIT: this would involve changing a text file or creating a new text file - AQA has never told students to do anything text file-based

C#:


Delphi/Pascal:


Java:


Python:

# Change to the AttemptPuzzle function 
    def AttemptPuzzle(self):
        Finished = False
        while not Finished:
            self.DisplayPuzzle()
            print("Current score: " + str(self.__Score))
            # Change
            CreatePattern = input('Would you like to make your own pattern? (y/n)\n').lower()
            if CreatePattern == 'y':
                self.makeNewPattern()
            # End


# Creation of new function in the Pattern class
# Change
    def makeNewPattern(self): # function is used to create new 3x3 patterns
        symbolAllowed = False
        while symbolAllowed != True:
            newSymbol = input('Please enter a symbol you would like to add to the game:\n').upper()
            if len(newSymbol) == 1: # making sure the length of the symbol entered is 1
                symbolAllowed = True
            else:
                pass
        patternAllowed = False
        while patternAllowed != True:
            newPattern = input('Please enter the new pattern (3x3):\n').upper()
            new = True
            for i in newPattern:
                if i != f'{newSymbol}' and i != '*': # the code checks if the pattern only contains * and the symbol chosen
                    new = False
            if len(newPattern) != 9: # making sure a 3x3 pattern is chosen
                new = False
            if new == True:
                patternAllowed = True
        patternName = Pattern(f'{newSymbol}',f'{newPattern}')
        print(patternName.GetPatternSequence())
        self.__AllowedPatterns.append(patternName)
        self.__AllowedSymbols.append(newSymbol) 
        # code above is the same as in the __init__() section and adds the new patterns to the allowed patterns list
        print('Would you like to make another pattern? (y/n)\n')
        choice = input().lower()
        if choice == 'y':
            self.makeNewPattern()
    # End


VB.NET:


Question 16- Making a difficulty rating program

edit

Description of problem:

1) this program can save each game in record including their score, number of symbols left, time to complete and the original empty grid

2) using these information to make a difficulty rating board, so the user can see their rating and select the one they want to play

C#:


Delphi/Pascal:


Java:


Python:


VB.NET:


Question 19 - Advanced Wild Card [13 marks]

edit

This questions refers to the class Puzzle. A new option of a wildcard is to be added to the game. When the player uses this option, they are given the opportunity to complete a pattern by overriding existing symbols to make that pattern. The wildcard can only be used once in a game.

Task 1:

Add a new option for the user that will appear before each turn. The user should be asked "Do you want to use your wildcard (Y/N)" If the user responds with "Y" then the Row, Column and Symbol will be taken as normal but then the new method ApplyWildcard should be called and the prompt for using the wildcard should no longer be shown in subsequent turns. If the user responds with "N" then the puzzle continues as normal.

Task 2:

Create a new method called ApplyWildcard that will take the Row, Column and Symbol as parameters and do the following:

1. Determine if the pattern can be completed in a 3x3 given the Row, Column and Symbol passed to it.

a) If the pattern can be made the cells in the pattern should be updated using the method UpdateCell() in the Cell class and 5 points added for move.

b) If the pattern cannot be made the user should be given the message "Sorry, the wildcard does not work for this cell – you have no wildcards left"

C#:


Delphi/Pascal:


Java:


Python:

class Puzzle():
    def __init__(self, *args):
        if len(args) == 1:
            self.__Score = 0
            self.__SymbolsLeft = 0
            self.__GridSize = 0
            self.__Grid = []
            self.__AllowedPatterns = []
            self.__AllowedSymbols = []
            self.__LoadPuzzle(args[0])
            # Change 
            self.__WildCard = False
            # End
        else:
            self.__Score = 0
            self.__SymbolsLeft = args[1]
            self.__GridSize = args[0]
            self.__Grid = []
            # Change
            self.__WildCard = False
            # End
            for Count in range(1, self.__GridSize * self.__GridSize + 1):
                if random.randrange(1, 101) < 90:
                    C = Cell()
                else:
                    C = BlockedCell()
                self.__Grid.append(C)
            self.__AllowedPatterns = []
            self.__AllowedSymbols = []
            QPattern = Pattern("Q", "QQ**Q**QQ")
            self.__AllowedPatterns.append(QPattern)
            self.__AllowedSymbols.append("Q")
            XPattern = Pattern("X", "X*X*X*X*X")
            self.__AllowedPatterns.append(XPattern)
            self.__AllowedSymbols.append("X")
            TPattern = Pattern("T", "TTT**T**T")
            self.__AllowedPatterns.append(TPattern)
            self.__AllowedSymbols.append("T")


# Altercation of attempt puzzle class to ask the user if they would like to use their wildcard
    def AttemptPuzzle(self):
        Finished = False
        while not Finished:
            self.DisplayPuzzle()
            print("Current score: " + str(self.__Score))
            # Change
            wild = False
            if self.__WildCard == False:
                useWildCard = input('Would you like to use your wildcard (Y/N)?\n').upper()
                if useWildCard == 'Y':
                    self.__WildCard = True
                    wild = True
            Row = -1
            Valid = False
            while not Valid:
                try:
                    Row = int(input("Enter row number: "))
                    Valid = True
                except:
                    pass
            Column = -1
            Valid = False
            while not Valid:
                try:
                    Column = int(input("Enter column number: "))
                    Valid = True
                except:
                    pass
            Symbol = self.__GetSymbolFromUser()
            self.__SymbolsLeft -= 1
            if wild == False:
                CurrentCell = self.__GetCell(Row, Column)
                if CurrentCell.CheckSymbolAllowed(Symbol):
                    CurrentCell.ChangeSymbolInCell(Symbol)
                    AmountToAddToScore = self.CheckforMatchWithPattern(Row, Column)
                    if AmountToAddToScore > 0:
                        self.__Score += AmountToAddToScore
            elif wild == True:
                AmountToAddToScore = self.ApplyWildCard(Row,Column,Symbol)
                if AmountToAddToScore > 0:
                    self.__Score += AmountToAddToScore
            # End
            if self.__SymbolsLeft == 0:
                Finished = True
        print()
        self.DisplayPuzzle()
        print()
        return self.__Score


# Change - new function created to check if the symbol added is allowed and will create a new symbol
    def ApplyWildCard(self, Row, Column, Symbol):
        # Assuming the wildcard cannot be placed on a blocked cell as does not state
        currentCell = self.__GetCell(Row,Column)
        if currentCell.GetSymbol() != BlockedCell():
            currentCell.ChangeSymbolInCell(Symbol)

        for StartRow in range(Row + 2, Row - 1, -1):
            for StartColumn in range(Column - 2, Column + 1):
                try:
                    PatternString = ""
                    PatternString += self.__GetCell(StartRow, StartColumn).GetSymbol()
                    PatternString += self.__GetCell(StartRow, StartColumn + 1).GetSymbol()
                    PatternString += self.__GetCell(StartRow, StartColumn + 2).GetSymbol()
                    PatternString += self.__GetCell(StartRow - 1, StartColumn + 2).GetSymbol()
                    PatternString += self.__GetCell(StartRow - 2, StartColumn + 2).GetSymbol()
                    PatternString += self.__GetCell(StartRow - 2, StartColumn + 1).GetSymbol()
                    PatternString += self.__GetCell(StartRow - 2, StartColumn).GetSymbol()
                    PatternString += self.__GetCell(StartRow - 1, StartColumn).GetSymbol()
                    PatternString += self.__GetCell(StartRow - 1, StartColumn + 1).GetSymbol()
                    print(PatternString)
                    for P in self.__AllowedPatterns:
                        CurrentSymbol = self.__GetCell(Row, Column).GetSymbol()
                        if P.MatchesPattern(PatternString, CurrentSymbol):
                            self.__GetCell(StartRow, StartColumn).AddToNotAllowedSymbols(CurrentSymbol)
                            self.__GetCell(StartRow, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol)
                            self.__GetCell(StartRow, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol)
                            self.__GetCell(StartRow - 1, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol)
                            self.__GetCell(StartRow - 2, StartColumn + 2).AddToNotAllowedSymbols(CurrentSymbol)
                            self.__GetCell(StartRow - 2, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol)
                            self.__GetCell(StartRow - 2, StartColumn).AddToNotAllowedSymbols(CurrentSymbol)
                            self.__GetCell(StartRow - 1, StartColumn).AddToNotAllowedSymbols(CurrentSymbol)
                            self.__GetCell(StartRow - 1, StartColumn + 1).AddToNotAllowedSymbols(CurrentSymbol)
                            print('Your wildcard has worked')
                            return 5
                except:
                    pass
        print('Sorry the wildcard does not work for this cell - you have no wildcards left')
        return 0
    # End


Question 20 - Shuffle all the blocked cells [9 marks]

edit

Implement a feature where the user can shuffle the blocked cells around.

  • The new blocked cells cannot be in the same place as they were before
  • They cannot overlap a matched pattern or symbol placed

Python:

def AttemptPuzzle(self):
        #Start of Change
        Finished = False
        while not Finished:
            self.DisplayPuzzle()
            if input("Do you want to reshuffle all the blocked cells?[y/n]: ").lower() == 'y':
                self.ReShuffleBlockedCells()
                self.DisplayPuzzle()
        #End of Change

def ReShuffleBlockedCells(self): #I've done this by creating a new method in the Puzzle class
        indexstore = []
        for i, cell in enumerate(self.__Grid):
            if isinstance(cell, BlockedCell):
                indexstore.append(i)

        for num in indexstore:
            checker = True
            while checker:
                a = random.randint(1, (self.__GridSize**2)-1)
                if a not in indexstore:
                    if self.__Grid[a].IsEmpty():
                        checker = False
            self.__Grid[num] = Cell() 
            self.__Grid[a] = BlockedCell()

Question 21 - A challenge option - where The letters the user has to place down will be randomly generated and if the user successfully does it they gain points otherwise they will lose points (10 marks)