dfs：马踏棋盘

#include<stdio.h>
#include<time.h>

#define X 8
#define Y 8

int chess[X][Y];

//查找当前位置的下一个位置
int nextxy(int* x, int* y, int count)
{
    switch (count)
    {
    case 0:
        if (*x + 2 <= X - 1 && *y - 1 >= 0 && chess[*x + 2][*y - 1] == 0)
        {
            *x += 2;
            *y -= 1;
            return 1;
        }
        break;

    case 1:
        if (*x + 2 <= X - 1 && *y + 1 <= Y - 1 && chess[*x + 2][*y + 1] == 0)
        {
            *x += 2;
            *y += 1;
            return 1;
        }
        break;

    case 2:
        if (*x + 1 <= X - 1 && *y + 2 <= Y - 1 && chess[*x + 1][*y + 2] == 0)
        {
            *x += 1;
            *y += 2;
            return 1;
        }
        break;

    case 3:
        if (*x - 1 >= 0 && *y + 2 <= Y - 1 && chess[*x - 1][*y + 2] == 0)
        {
            *x -= 1;
            *y += 2;
            return 1;
        }
        break;
        
    case 4:
        if (*x - 2 >= 0 && *y + 1 <= Y - 1 && chess[*x - 2][*y + 1] == 0)
        {
            *x -= 2;
            *y += 1;
            return 1;
        }
        break;

    case 5:
        if (*x - 2 >= 0 && *y - 1 >= 0 && chess[*x - 2][*y - 1] == 0)
        {
            *x -= 2;
            *y -= 1;
            return 1;
        }
        break;
        
    case 6:
        if (*x - 1 >= 0 && *y - 2 >= 0 && chess[*x - 1][*y - 2] == 0)
        {
            *x -= 1;
            *y -= 2;
            return 1;
        }
        break;

    case 7:
        if (*x + 1 <= X - 1 && *y - 2 >= 0 && chess[*x + 1][*y - 2] == 0)
        {
            *x += 1;
            *y -= 2;
            return 1;
        }
        break;
    default:
        break;
    }

    return 0;
}

void print()
{
    int i, j;
    for (i = 0; i < X; i++)
    {
        for (j = 0; j < Y; j++)
        {
            printf("%2d	", chess[i][j]);
        }
        printf("
");
    }

    printf("
");
}

//深度优先遍历
//(x,y)为位置坐标
//tag为标记变量，每走一步，tag+1
int TravelChessBoard(int x, int y, int tag)
{
    int x1 = x;
    int y1 = y;
    int flag = 0;
    int count = 1;
    chess[x][y] = tag;

    if (tag == X * Y)
    {
        //打印棋盘
        print();
        return 1;
    }
    //找到马的下一个可走坐标（x1，y1），如果找到flag = 1，否则为0
    flag = nextxy(&x1, &y1, count);
    while (flag == 0 && count < 8)
    {
        count++;
        flag = nextxy(&x1, &y1, count);
    }


    while (flag)
    {
        if (TravelChessBoard(x1, y1, tag + 1))
        {
            return 1;
        }

        //继续找到马的下一步的可走的坐标（x1，y1），如果找到flag = 1，否则为0
        x1 = x;
        y1 = y;
        count++;

        flag = nextxy(&x1, &y1, count);
        while (flag == 0 && count < 8)
        {
            count++;
            flag = nextxy(&x1, &y1, count);
        }
    }

    if (flag == 0)
    {
        chess[x][y] = 0;
    }

    return 0;
}

int main()
{
    int i, j;
    clock_t start, finish;

    start = clock();

    for (i = 0; i < X; i++)
    {
        for (j = 0; j < Y; j++)
        {
            chess[i][j] = 0;
        }
    }

    printf("下面开始马踏棋盘：
");
    if (!TravelChessBoard(1, 0, 1))
    {
        printf("马踏棋盘失败了
");
    }

    finish = clock();
    printf("
本次计算义工耗时：%f

", (double)(finish - start) / CLOCKS_PER_SEC);

    return 0;
}

程序没问题，但是再vs上运行了好久也没运行出来