关于c语言三子棋的问题，如何解决？

Question

下了一步棋就判断平局了。自己一直没找到问题出在哪里。

#define _CRT_SECURE_NO_WARNINGS
#define ROW 3
#define COL 3
#include<stdlib.h>
#include<stdio.h>
#include<string.h>
#include<time.h>


//声明
void initboard(char board[ROW][COL], int row, int col);
void DisplayBoard(char board[ROW][COL], int row, int col);
void playermove(char board[ROW][COL], int row, int col);
void computmove(char board[ROW][COL], int row, int col);
char iswin(char board[ROW][COL], int row, int col);

#define _CRT_SECURE_NO_WARNINGS
#include"game.h"


void initboard(char board[ROW][COL], int row, int col)
{
    int a = 0;
    for (a = 0; a < row; a++)
    {
        int b = 0;
        for (b = 0; b < col; b++)
        {
            board[a][b] = ' ';
        }
    }
}
void DisplayBoard(char board[ROW][COL], int row, int col)
{
    int a = 0;
    for (a = 0; a < row; a++)
    {
        int b = 0;
        for (b = 0; b < col; b++)
        {
            printf(" %c ", board[a][b]);
            if (b < row - 1)
            {
                printf("|");
            }
        }
        printf("\n");
        if (a < row - 1)
        {
            for (b = 0; b < col; b++)
            {
                printf("---");
                if (b < col - 1)
                {
                    printf("|");
                }
            }
            printf("\n");
        }
    }
    printf("\n");
}
void playermove(char board[ROW][COL], int row, int col)
{
    int x = 0; int y = 0;
    printf("玩家下棋\n");
    printf("请输入要走的位置：");
    scanf("%d %d", &x, &y);
    if (x >= 1 && x  <= row && y  >= 1 && y  <= col)
    {
        if (board[x-1][y-1] == ' ')
        {
            board[x-1][y-1] = '*';
        }
        else
        {
            printf("坐标被占用");
        }
    }
    else
        printf("坐标非法\n");
}
void computmove(char board[ROW][COL], int row, int col)
{
    int x = 0; int y = 0;
    printf("电脑下棋\n");
    while (1)
    {
        x = rand() % row;//0-2
        y = rand() % col;
        if (board[x][y] == ' ')
        {
            board[x][y] = '#';
            break;
        }
    }
}
//棋盘满了返回1
//棋盘没满返回0
int isfull(char board[ROW][COL],int row,int col)
{
    int a = 0; 
    for (a = 0; a < row; a++)
    {
        int b = 0;
        for (b = 0; b < col; b++)
        {
            if (board[a][b] == ' ');
            {
                return 0;
            }
        }
    }
    return 1;
}

char iswin(char board[ROW][COL], int row, int col)
{
    int a = 0;
    //横三行
    for (a = 0; a < row; a++)
    {
        if (board[a][0] == board[a][1] && board[a][1] == board[a][2] && board[a][1] != ' ');
        {
            return board[a][1];
        }
    }
    //竖三列
    for (a = 0; a < col; a++)
    {
        if (board[0][a] == board[1][a] && board[0][a] ==board[2][a] && board[0][a] != ' ');
        {
            return board[0][a];
        }
    }
    if (board[0][0] == board[1][1] && board[1][1] == board[2][2] && board[1][1] != ' ');
    {
        return board[0][0];
    }
    if (board[0][2] == board[1][1] && board[1][1] == board[2][0] && board[1][1] != ' ');
    {
        return board[1][1];
    }
    if (1 == isfull(board, ROW, COL))
    {
        return 'q';
    }
    return 'C';
}

#define _CRT_SECURE_NO_WARNINGS
#include"game.h"
void game()
{
    char ret = 0;
    char board[ROW][COL] = { 0 };
    //初始化数组
    initboard(board, ROW, COL);
    //打印棋盘
    DisplayBoard(board, ROW, COL);
    while (1)
    {
        //玩家下棋
        playermove(board, ROW, COL);
        DisplayBoard(board, ROW, COL);
        //判断玩家是否赢
        ret = iswin(board,ROW,COL);
        if (ret != 'C')
        {
            break;
        }
        //电脑下棋
        computmove(board, ROW, COL);
        DisplayBoard(board, ROW, COL);
        //判断电脑是否赢
        ret = iswin(board, ROW, COL);
        if (ret != 'C')
        {
            break;
        }
    }
    if (ret == '*')
    {
        printf("玩家赢\n");
    }
    else if (ret == '#')
    {
        printf("电脑赢\n");
    }
    else
    {
        printf("平局\n");
    }
}
void menu()
{
    printf("*****************\n");
    printf("*****1.play *****\n");
    printf("*****0.exit *****\n");
    printf("*****************\n");
}
void test()
{
    int input = 0;
    srand((unsigned int)time(NULL));
    do
    {
        menu();
        printf("请选择：");
        scanf("%d", &input);
        switch (input)
        {
        case 1:
            game();
            break;
        case 0:
            printf("退出游戏");
            break;
        default:
            printf("输入错误！");
            break;
        }
    } while (input);
}
int main()
{
    test();
    return 0;
}

Answer 1

问题出在iswin()函数中判断语句后面多了分号，使该判断语句后面的大括号中的代码始终会被执行，即使条件不满足。在本程序中，iswin()函数中四个if语句都多了分号，导致平局的情况无法正确判断。

将iswin()函数中的四个if语句中的分号去掉即可。

修改后的iswin()函数代码如下：

char iswin(char board[ROW][COL], int row, int col)
{
    int a = 0;
    //横三行
    for (a = 0; a < row; a++)
    {
        if (board[a][0] == board[a][1] && board[a][1] == board[a][2] && board[a][1] != ' ')
        {
            return board[a][1];
        }
    }
    //竖三列
    for (a = 0; a < col; a++)
    {
        if (board[0][a] == board[1][a] && board[0][a] ==board[2][a] && board[0][a] != ' ')
        {
            return board[0][a];
        }
    }
    if (board[0][0] == board[1][1] && board[1][1] == board[2][2] && board[1][1] != ' ')
    {
        return board[0][0];
    }
    if (board[0][2] == board[1][1] && board[1][1] == board[2][0] && board[1][1] != ' ')
    {
        return board[1][1];
    }
    if (1 == isfull(board, ROW, COL))
    {
        return 'q';
    }
    return 'C';
}