C# Bingo Algorithm for Checking BIngo

Question

I have a 5x5 2D array of type Boolean and I want to check for vertical, horizontal, and diagonal bingo.

If values at those specific cells are set to "true", I get a bingo. Otherwise, I continue to play the game. I was looking for help to improve, or get feedback to completely re-haul this method for checking for a Bingo.

public int checkForBingo(int rowID, int colID) 
{    
    bool winner = false;

    for (int i = 0; i < 4; i++)
    {
        //checking verts and horiz
        if (winner = (boardState[i, 0]) == true && (boardState[i, 1] == true)
            && (boardState[i, 2] == true) && (boardState[i, 3] == true)
              && (boardState[i, 4] == true))
            break;
        else if (winner = (boardState[0, i] == true) && (boardState[1, i] == true)
            && (boardState[2, i] == true) && (boardState[3, i] == true) &&
            (boardState[4, i] == true))
            break;

        //checking diagonals
        if (!winner)
        {
            if (boardState[2, 2] == true)
                if ((winner = (boardState[0, 0] == true) && (boardState[1, 1] == true) &&
                    (boardState[3, 3] == true) && (boardState[4, 4] == true)))
                    break;
                else if (!(winner = (boardState[0, 4] == true) && (boardState[1, 3] == true) &&
                        (boardState[3, 1] == true) && (boardState[4, 0] == true)))
                    break;
        }
    }
    return 0;
}

Answer 1

For loop run from i=0 to 3 That means it's checking 4 rows only and in if condition you are checking for all 5 columns which is right. Change your for loop condition to

i <= 4

Answer 2

A few thing to note:

• The main for loop should go be for (int i = 0; i < 5; i++) less than 5 ( arrays are 0 based)

• You dont need to check for == true, a boolean value can be simple encapsulated in a if statement such as:

  if (boardState[0, 4] && boardState[1, 3] && boardState[3, 1] && boardState[4, 0])

• The assignment in the if could lead to unwanted behavior(side effects) easy to forget is there.
• The method signature should be capitalized ergo CheckForBingo
• If you are not using the parameters - then remove them from the method signature
• As noted the code is a bit hard to follow

For comparison and learning purpose(myself included) I have written the method like this:

public bool CheckForBingo(bool[,] boardState)
        {
            bool haveWeWon = false;

            //check horizotal
            for (int i = 0; i < 5; i++)
            {
                haveWeWon = true;

                for (int y = 0; y < 5; y++)
                {
                    if (!boardState[i, y])
                    {
                        haveWeWon = false;
                        break;
                    }
                }

                if(haveWeWon)
                {
                    return haveWeWon;
                }
            }

            if (!haveWeWon)
            {
                //check vertical
                for (int i = 0; i < 5; i++)
                {
                    haveWeWon = true;

                    for (int y = 0; y < 5; y++)
                    {
                        if (boardState[y, i])
                        {
                            haveWeWon = false;
                            break;
                        }
                    }

                    if (haveWeWon)
                    {
                        return haveWeWon;
                    }
                }
            }

            //check the middle - if false dont bother checking diagonal
            if (boardState[2, 2])
            {
                if (!haveWeWon)
                {
                    //check top left diagonal 
                    for (int i = 0; i < 5; i++)
                    {
                        haveWeWon = true;

                        if (!boardState[i, i])
                        {
                            haveWeWon = false;
                            break;
                        }
                    }

                    if (haveWeWon)
                    {
                        return haveWeWon;
                    }
                }

                if (!haveWeWon)
                {
                    //check top right diagonal 
                    for (int i = 4; i >= 0; i--)
                    {
                        haveWeWon = true;

                        if (!boardState[i, i])
                        {
                            haveWeWon = false;
                            break;
                        }
                    }

                    if (haveWeWon)
                    {
                        return haveWeWon;
                    }
                }
            }
            return false;
        }