Question

Please have a look at the following code

#include <iostream>
#include <stdlib.h>
#include <ctime>

using namespace std;

const char PLAYER_1 = 'O';
const char PLAYER_2 = 'X';


int row = 0;
int col = 0;

int winningStates[8][3][2] = {{{0,0},{0,1},{0,2}},{{1,0},{1,1},{1,2}},{{2,0},{2,1},{2,2}},{{3,0},{3,1},{3,2}},
                                {{4,0},{4,1},{4,2}},{{5,0},{5,1},{5,2}},{{6,0},{6,1},{6,2}},{{7,0},{7,1},{7,2}}};

//This sets all the elements within the body to '-' to indicate that the square is free
void intialise(char board[][3])
{
    for(int i=0;i<3;i++)
    {
        for(int a=0;a<=3;a++)
        {
            board[i][a] = '-';

        }
    }


}

//This displays the board on the screen
void display(char board[][3])
{
    for(int i=0;i<3;i++)
    {
        for(int a=0;a<3;a++)
        {
            cout << board[i][a] << "\t ";

        }
        cout << endl;
    }
}

//setValue() sets the cell indicated by the parameter to the value that is contained within the symbol parameter
void setValue(int row, int col, char symbol, char board[][3])
{
    board[row][col] = symbol;
}

//isFree() returns true if the cell identified by the parameter contains '-'
bool isFree(int row, int col, char board[][3])
{
    if(board[row][col]=='-')
    {
        return (true);
    }
    else
    {
        return (false);
    }
}

bool hasWon(char symbol,char board[][3])
{
    bool match = false;

    row = 0;
    col = 0;

    for(int m=0;m<8;m++)
    {
        for(int s=0;s<3;s++)
        {
            row = winningStates[m][s][0];
            col = winningStates[m][s][1];

            if(board[row][col]==symbol)
            {
                match = true;
            }
            else
            {
                match = false;
                break;
            }
        }
    }
    return match;
    //return false;
}

int main()
{
    char board[3][3];

    srand(time(0));

    bool gameOver = false;

    char player = PLAYER_1;

    int count = 0;

    intialise(board);
   // display();

    while(gameOver!=true)
    {     

        do
        {
            row = rand()%3;
            col = rand()%3;
        }
        while(! isFree(row,col,board));


        setValue(row,col,player,board);
        if(player==PLAYER_1)
        {
            player = PLAYER_2;
        }
        else
        {
            player = PLAYER_1;
        }

        gameOver = hasWon(player,board);

        if(gameOver==true)
        {
            cout << "WON" << endl;
        }
        count++;

        if(count==9)
        {
            gameOver = true;
            break;
        }


        display(board);
        cout << endl;


    }
}

In this code, I never get “WON” message. And, one cell is always free, without any symbol.
It doesn’t matter how many times I run this code, No one wins!! Why is this? Please help!!

Answer 1

It looks like a logic error, try this

bool hasWon(char symbol,char board[][3])
{
    for(int m=0;m<8;m++)
    {
        bool found_line = true;
        for(int s=0;s<3;s++)
        {
            int row = winningStates[m][s][0];
            int col = winningStates[m][s][1];

            if(board[row][col]!=symbol)
            {
                found_line = false;
                break;
            }
        }
        if (found_line)
            return true;
    }
    return false;
}

I think it helps to choose better variable names for this kind of task, match is not very good because it doesn’t say what you are matching. Which seems to have been your error.