算法学习之8皇后问题

#include <iostream>
#include <cstdio>
#include <vector>
#include <cstring>
#include <cmath>
using namespace std;
int arry[8][8]; //打印数组用的
int t = 0; //计算总共次数
void search_answer(unsigned char flag[],int n)
{
    if(n == 8)
    {
        for(int i = 0; i < n; i++)
        {
            arry[i][flag[i]] = 1;
        }
        for(int i = 0; i < n; i++)
        {
            for(int j = 0; j < n; j++)
                printf("%d ",arry[i][j]);
            printf("\n");
        }
        printf("\n\n");
        memset(arry,0,sizeof(arry));
        t++;
    }
    else
    {
        for(int i = 0; i < 8; i++)
        {
            if(n == 0)
            {
                flag[n] = i;
                search_answer(flag,n+1);
            }
            else
            {
                unsigned char ok = 1;
                for(int j = 0; j < n; j++)
                {
                    if(flag[j] == i || n-j == abs(i-flag[j])) //不符合条件的剪枝
                    {
                       ok = 0;
                       break;
                    }
                }
                if(ok)
                {
                    flag[n] = i;
                    search_answer(flag,n+1);
                }
            }
        }
    }
}
int main()
{
    unsigned char flag[8]; //代表每行的皇后处于第几列，i代表第行，flag[i]代表第i列
    memset(flag,0,sizeof(flag));
    search_answer(flag,0); //从第0行开始查找
    printf("%d\n",t);
    return 0;
}