八皇后问题

#include <iostream>
#include <algorithm>
using namespace std;
#define MaxSize 100

int n, count_;
int queen[MaxSize];
int vis[3][MaxSize]={0};

void search_1(int cur){
    if(cur == n){
        count_++;
        printf("NO.%d\n", count_);
        for(int i=0; i<n; ++i){
            for(int j=0; j<n; ++j){
                if(queen[i] == j)  printf("%5d", 1);
                else printf("%5d", 0);
            }
            printf("\n");
        }
    }
    else{
        for(int i=0; i<n; ++i){
            queen[cur] = i;  //把皇后放在第cur行的第i列
            bool ok = true;
            for(int j=0; j<cur; ++j)
                if(queen[cur] == queen[j] || cur-queen[cur] == j-queen[j] || cur+queen[cur] == j+queen[j]){
                    ok = false; break;
                }
            if(ok) search_1(cur+1);
        }
    }
}

void search_2(int cur){
    if(cur == n){
        count_++;
        printf("NO.%d\n", count_);
        for(int i=0; i<n; ++i){
            for(int j=0; j<n; ++j){
                if(queen[i] == j)  printf("%5d", 1);
                else printf("%5d", 0);
            }
            printf("\n");
        }
    }
    else for(int col=0; col<n; ++col){
        //vis[0][]表示的现在的列有没有其他皇后，vis[1][]和vis[2][]表示现在的对角线有没有其他皇后
        if(!vis[0][col] && !vis[1][cur+col] && !vis[2][n+cur-col]){  
            queen[cur] = col;
            vis[0][col] = vis[1][cur+col] = vis[2][n+cur-col] = 1;
            search_2(cur+1);
            vis[0][col] = vis[1][cur+col] = vis[2][n+cur-col] = 0;
        }
    }
}

int main(){
    cin>>n;
    //search_1(0);
    search_2(0);
    return 0;
}