八皇后问题 C 语言代码

#include <stdio.h>
#include <math.h>

int c = 0;

void PrintTheChessBoard(int queens[], int n)
{
    int i, j;

    for (i = 0; i < n; i ++)
    {
        for (j = 0; j < queens[i]; j ++)
        {
            printf("L");
        }
        printf("1");
        for (j = n; j > queens[i]; j --)
        {
            printf("L");
        };
        putchar('\n');
    }
    printf("Please press enter to see the next answer\n");
    getch();

}

// 检查棋盘从第 0 行到第 i 行的布局是否合法。
int CheckTheChessBoard(int queens[], int i)
{
    int j, k;

    for (j = 0; j <= i; j ++)
    {
        for (k = 0; k <= i; k ++)
        {
            if (j != k && (queens[j] == queens[k] || abs(queens[j] - queens[k]) == abs(j - k)))
            {
                return 0;
            }
        }
    }

    return 1;
}

void Trial(int queens[], int i, int n)
{
    if (i >= n)
    {
        c ++;
        PrintTheChessBoard(queens, n);
    }
    else
    {
        int j;

        for (j = 0; j < n; j ++)
        {
            queens[i] = j;
            if (CheckTheChessBoard(queens, i))
            {
                Trial(queens, i + 1, n);
            }
        }
    }
}

void main()
{
    int queens[] = {-1, -1, -1, -1, -1, -1, -1, -1};

    Trial(queens, 0, sizeof(queens) / sizeof(int));
    printf("There is %d answers for the %d queen question", c, sizeof(queens) / sizeof(int));
    getch();
}