递归回溯--八皇后

　　

#include <stdio.h>

#define N 8

int matrix[N][N];    //棋盘矩阵
int cnt;

int Jude(int row, int col)
{
    int i,j;
    for (i = 0; i < row; i++)
    {
        for (j = 0; j < N; j++)
        {
            if (matrix[i][j] == 1)
                if( j == col || i + j == row + col
                || i - j == row - col || j - i == col -row
                || i + j == row + col)
            {
                return -1;
            }
        }
    }
    return 0;
}

void Print()
{
    int row, col;
    for (row = 0; row < N; row ++)
    {
        for (col = 0; col < N; col++)
        {
            printf("%d ",matrix[row][col]);
        }
        printf("
");
    }
    printf("
");
}

int Queen(int row)
{
    int col, ret;

    if (N == row)
    {
        Print();
        cnt ++;
        return 0;
    }

    for (col = 0; col < N; col++)
    {
        ret = Jude(row,col);
        if (0 == ret)
        {
            matrix[row][col] = 1;
            Queen(row + 1);
            matrix[row][col] = 0;
        }
    }

    if (col == N) return -1;    //无位置可填

    return 0;
}

int main()
{
    cnt = 0;

    Queen(0);
    printf("Total: %d
",cnt);

    return 0;
}

2013/11/10  10:40  cost:40