Question

My homework is to write a tic tac toe function, this code isn't working and I can not find the error. It prints the board and accepts user input just fine, the only problem is the checkBoard function. I can not get it to return a value(player win) to end the while loop.

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

int checkBoard(char board[3][3]) {
   int i, j;
   for (i = 0; i < 3; i += 1) {
       if ((board[i][0]=='X'&&board[i][1]=='X'&&board[i][2]=='X'))
           return 1;

       if ((board[i][0] == 'O'&&board[i][1] == 'O'&&board[i][2] == 'O'))
           return 2;
   }
   for (j = 0; j < 3; j += 1) {
       if (board[0][j]=='X'&&board[1][j]=='X'&&board[1][j]=='X')
           return 1;
       if (board[0][j] == 'O'&&board[1][j] == 'O'&&board[1][j] == 'O')
           return 2;
   }
   if (board[0][0]=='X'&&board[1][1]=='X'&&board[2][2]=='X')
       return 1;
   if (board[0][0] == 'O'&&board[1][1] == 'O'&&board[2][2] == 'O')
       return 2;
   if (board[0][2] == 'X'&&board[1][1] == 'X'&&board[2][0] == 'X')
       return 1;
   if (board[0][2] == 'X'&&board[1][1] == 'X'&&board[2][0] == 'X')
       return 2;
   else return 0;
  
}
void printBoard(char board[3][3]) {
   printf("%c | %c | %c\n",board[0][0],board[1][0],board[2][0]);
   printf("___|___|___\n");
   printf("%c | %c | %c\n", board[0][1], board[1][1], board[2][1]);
   printf("___|___|___\n");
   printf("%c | %c | %c\n", board[0][2], board[1][2], board[2][2]);
   printf(" | | \n\n\n\n");
}

int main() {
   char board[3][3];
   int i, j, x, y;
   for (i = 0; i < 3; i += 1) {
       for (j = 0; j < 3; j += 1) {
           board[j][i] = ' ';
       }
   }

   while (checkBoard(board) != 1 || checkBoard(board) != 2 || checkBoard(board) != 0) {
       printBoard(board);
       printf("X turn: Enter location 'x y': ");
       scanf("%d %d", &x, &y);
       while (board[x][y] == 'X' || board[x][y] == 'O') {
           printf("Spot taken choose again 'x y': ");
           scanf("%d %d", &x, &y);
       }
       board[x][y] = 'X';
       printBoard(board);
       checkBoard(board);
       printf(" O turn: ");
       scanf("%d %d", &x, &y);
       while (board[x][y] == 'X' || board[x][y] == 'O') {
           printf("Spot taken choose again 'x y': ");
           scanf("%d %d", &x, &y);
       }
       board[x][y] = 'O';
       checkBoard(board);
   }
   printBoard(board);
   if (checkBoard(board) == 1) {
       printf("X's Win!\n");
   }
   if (checkBoard(board) == 2) {
       printf("O's Win!\n");
   }
   if (checkBoard(board) == 0) {
       printf("Tie game!\n");
   }
       return 0;
  
}

Answer 1

Program -

#include <stdio.h>
#include <conio.h>

char positionBoard[10] = { 'o', '1', '2', '3', '4', '5', '6', '7', '8', '9' };

int checkBoard();
void printBoard();

int main()
{
int playerTurn = 1, i, userChoice;

char mark;
do
{
printBoard();
playerTurn = (playerTurn % 2) ? 1 : 2;

printf("Player %d, enter a number: ", playerTurn);
scanf("%d", &userChoice);

mark = (playerTurn == 1) ? 'X' : 'O';

if (userChoice == 1 && positionBoard[1] == '1')
positionBoard[1] = mark;
  
else if (userChoice == 2 && positionBoard[2] == '2')
positionBoard[2] = mark;
  
else if (userChoice == 3 && positionBoard[3] == '3')
positionBoard[3] = mark;
  
else if (userChoice == 4 && positionBoard[4] == '4')
positionBoard[4] = mark;
  
else if (userChoice == 5 && positionBoard[5] == '5')
positionBoard[5] = mark;
  
else if (userChoice == 6 && positionBoard[6] == '6')
positionBoard[6] = mark;
  
else if (userChoice == 7 && positionBoard[7] == '7')
positionBoard[7] = mark;
  
else if (userChoice == 8 && positionBoard[8] == '8')
positionBoard[8] = mark;
  
else if (userChoice == 9 && positionBoard[9] == '9')
positionBoard[9] = mark;
  
else
{
printf("Invalid move ");

playerTurn--;
getch();
}
i = checkBoard();

playerTurn++;
}while (i == - 1);
  
printBoard();
  
if (i == 1)
printf("==>\aPlayer %d win ", --playerTurn);
else
printf("==>\aGame draw");

getch();

return 0;
}

/*This function is used to check the game status and return 1 if game is over -1 for game in progress 0 if game is over*/
int checkBoard()
{
if (positionBoard[1] == positionBoard[2] && positionBoard[2] == positionBoard[3])
return 1;
  
else if (positionBoard[4] == positionBoard[5] && positionBoard[5] == positionBoard[6])
return 1;
  
else if (positionBoard[7] == positionBoard[8] && positionBoard[8] == positionBoard[9])
return 1;
  
else if (positionBoard[1] == positionBoard[4] && positionBoard[4] == positionBoard[7])
return 1;
  
else if (positionBoard[2] == positionBoard[5] && positionBoard[5] == positionBoard[8])
return 1;
  
else if (positionBoard[3] == positionBoard[6] && positionBoard[6] == positionBoard[9])
return 1;
  
else if (positionBoard[1] == positionBoard[5] && positionBoard[5] == positionBoard[9])
return 1;
  
else if (positionBoard[3] == positionBoard[5] && positionBoard[5] == positionBoard[7])
return 1;
  
else if (positionBoard[1] != '1' && positionBoard[2] != '2' && positionBoard[3] != '3' &&
positionBoard[4] != '4' && positionBoard[5] != '5' && positionBoard[6] != '6' && positionBoard[7]
!= '7' && positionBoard[8] != '8' && positionBoard[9] != '9')

return 0;
else
return - 1;
}

//this function is used to draw board at with player mark on the board
void printBoard()
{
system("cls");
printf("\n\n\tTic Tac Toe\n\n");

printf("Player 1 (X) - Player 2 (O)\n\n\n");

printf(" | | \n");
printf(" %c | %c | %c \n", positionBoard[1], positionBoard[2], positionBoard[3]);

printf("_____|_____|_____\n");
printf(" | | \n");

printf(" %c | %c | %c \n", positionBoard[4], positionBoard[5], positionBoard[6]);

printf("_____|_____|_____\n");
printf(" | | \n");

printf(" %c | %c | %c \n", positionBoard[7], positionBoard[8], positionBoard[9]);

printf(" | | \n\n");
}

Screenshots -