gistfile1.c

#include <stdlib.h>
#include <stdio.h>

char check_board(char board[3][3]){
    for (int i = 0; i < 3; ++i){
        if (board[i][0] == board[i][1] && board[i][1] == board[i][2]){
            if (board[i][0] != '?'){
                return board[i][0];
            }
        }
        if (board[0][i] == board[1][i] && board[1][i] == board[2][i]){
            if (board[0][i] != '?'){
                return board[0][i];
            }
        }
    }
    if (board[0][0] == board[1][1] && board[1][1] == board[2][2]){
        if (board[0][0] != '?'){
            return board[0][0];
        }
    }
    if (board[0][2] == board[1][1] && board[1][1] == board[2][0]){
        if (board[0][2] != '?'){
            return board[0][2];
        }
    }
    return '?';
}

int main(){
    char board[3][3] =
    {
        {'?', '?', '?'},
        {'?', '?', '?'},
        {'?', '?', '?'}
    };
    char winner = ' ';
    char current = 'X';
    int moves = 0;
    int target = -1;
    
    while (moves < 9){
        system("cls");
        printf("%c's turn! Please enter 1-9 to make your move.\n\n", current);
        for (int i = 0; i < 3; i++){
            printf("%c %c %c\n", board[i][0], board[i][1], board[i][2]);
        }
        winner = check_board(board);
        if (winner != '?'){
            break;
        }
        printf("\n");
        scanf("%d", &target);
        --target;
        if (target < 0 || target > 9 || board[target / 3][target % 3] != '?'){
            continue;
        }
        board[target / 3][target % 3] = current;
        
        current = (current == 'X') ? 'O' : 'X';
        ++moves;
    }
    switch (winner){
        case '?':
            printf("Tie!\n");
            break;
        case 'X':
            printf("X Wins!\n");
            break;
        case 'O':
            printf("O Wins!\n");
            break;
            
    }
    system("pause");
    
    return 0;
}