求助,dfs为什么输出全是0

P1162 填涂颜色

这道题的标签是```BFS```不太适合用```DFS```做 可以参考一下[P1506 拯救oibh总部](https://www.luogu.com.cn/problem/P1506) 这题这样写: ``` #include<bits/stdc++.h> using namespace std; struct data{ int x,y; }; queue<data>q; int n,a[1001][1001]; bool vis[1001][1001]; void bfs(int x,int y){ vis[x][y]=1; q.push({x,y}); while(!q.empty()){ int w=q.front().x,e=q.front().y; q.pop(); if(a[w+1][e]==0 && w!=n && !vis[w+1][e]){ vis[w+1][e]=1; q.push({w+1,e}); } if(a[w-1][e]==0 && w!=1 && !vis[w-1][e]){ vis[w-1][e]=1; q.push({w-1,e}); } if(a[w][e-1]==0 && e!=1 && !vis[w][e-1]){ vis[w][e-1]=1; q.push({w,e-1}); } if(a[w][e+1]==0 && e!=n && !vis[w][e+1]){ vis[w][e+1]=1; q.push({w,e+1}); } } } int main(){ cin>>n; for(int i=1;i<=n;i++){ for(int j=1;j<=n;j++){ cin>>a[i][j]; if(a[i][j]==1)vis[i][j]=1; } } for(int i=1;i<=n;i+=n-1){ for(int j=1;j<=n;j++){ if(vis[i][j])continue; bfs(i,j); } } for(int i=1;i<=n;i+=n-1){ for(int j=1;j<=n;j++){ if(vis[j][i])continue; bfs(j,i); } } for(int i=1;i<=n;i++){ for(int j=1;j<=n;j++){ if(vis[i][j]==0)cout<<"2 "; else cout<<a[i][j]<<' '; } cout<<'\n'; } return 0; } ```
by QAQ_YTH @ 2023-02-17 22:10:51


或者看看题解学学别的大神的做法,也可以做出来。洛谷的题都有一些详细的[题解](https://www.luogu.com.cn/problem/solution/P1162),相信像我这样的蒟蒻也都能看懂的
by QAQ_YTH @ 2023-02-17 22:33:22


@[LxSmill](/user/733980) 这是我这道题的深搜代码 希望可以帮到你 ```cpp #include <bits/stdc++.h> using namespace std; int a[35][35],vist[35][35]; long long n; void dfs(int i,int j){ if(i<0||j<0||i>n+1||j>n+1||vist[i][j]!=0){ return; } vist[i][j]=1; dfs(i-1,j); dfs(i+1,j); dfs(i,j+1); dfs(i,j-1); } int main(){ cin>>n; for(int i=1;i<=n;i++){ for(int j=1;j<=n;j++){ cin>>a[i][j]; if(a[i][j]==0){ vist[i][j]=0; }else{ vist[i][j]=2; } } } dfs(0,0); for(int i=1;i<=n;i++){ for(int j=1;j<=n;j++){ if(vist[i][j]==0){ cout<<"2"<<" "; }else{ cout<<a[i][j]<<" "; } } cout<<endl; } return 0; } ```
by _Mikasa @ 2023-03-01 20:06:39


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