八皇后（dfs 模版

题源链接

#include<bits/stdc++.h>#include<iostream>usingnamespacestd;constintN=15;introw[N],sState[N*2],uState[N*2];//row是第i行，sstate是棋盘从左下到右上的规律：和相等//ustate是棋盘从左上到右下的规律：列与行差相等intres[N][N];//表示棋盘intn;voiddfs(intnum){//表示第num行if(num>n){for(inti=1;i<=n;i++){for(intj=1;j<=n;j++){if(res[i][j]){cout<<"Q";}else{cout<<".";}}cout<<"\n";}cout<<"\n";return;}for(inti=1;i<=n;i++){if(row[i]==0&&sState[num+i]==0&&uState[i-num]==0){//同时满足，就能确定一个点满足条件// cout<<num<<"---"<<i<<"\n";row[i]=1;sState[num+i]=uState[i-num]=1;res[num][i]=1;dfs(num+1);res[num][i]=0;row[i]=0;sState[num+i]=uState[i-num]=0;}}return;}intmain(){cin>>n;dfs(1);return0;}