实验四——回溯法·n皇后

/*Hatsune Miku 4ever!*/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define _for(i,a,b) for(int i = (a);i < b;i ++)
#define _rep(i,a,b) for(int i = (a);i > b;i --)
#define INF 0x3f3f3f3f3f3f3f3f
#define lowbit(x) ((x)&(-x))
#define pb push_back
#define MIKU 39
#define Design ios::sync_with_stdio(0),cin.tie(0),cout.tie(0)
#define debug() printf("Miku Check OK!\n")
#define bigmiku 3939393939
#define LOG 18
#define maxn 20
#define maxe 200039

int mp[maxn][maxn];
int vis[3][maxn*maxn];
int cnt = 1;
void dfs(int cur, int n)
{
    if(cur==n+1)
    {
        printf("第 %d 种:\n",cnt);
        _for(i,1,n+1)
        {
            _for(j,1,n+1)
            printf("%c ",mp[i][j]);
            printf("\n");
        }
        printf("\n");
        cnt ++;
        return ;
    }
    _for(i,1,n+1)
        if(!vis[0][i]&&!vis[1][cur+i]&&!vis[2][cur-i+n])
        {
            mp[cur][i] = ‘Q‘;
            vis[0][i] = vis[1][cur+i] = vis[2][cur-i+n] = 1;
            dfs(cur+1,n);
            mp[cur][i] = ‘.‘;
            vis[0][i] = vis[1][cur+i] = vis[2][cur-i+n] = 0;
        }
}

int main()
{
    _for(i,0,maxn)
        _for(j,0,maxn)
            mp[i][j] = ‘.‘;
    int n;
    scanf("%d",&n);
    dfs(1,n);
    printf("%d 皇后一共有 %d 种\n",n,cnt-1);
    return 0;
}