注释模式
```
#include<bits/stdc++.h>
using namespace std;
long n,a[1010][1010],ans=0;
long bx[10]={0,-1,0,1,0};
long by[10]={0,0,-1,0,1};
void dfs(int ,int );
void dfs(int i,int j){
bool pd=0;
for(int k=1;k<=4;k++){
int q=i+bx[k];
int p=j+by[k];
if(a[q][p]!=1){
pd=1;//如果没有碰到墙
break;
}
}
if((i<=1||i>=n||j<=1||j>=n||a[i][j]!=0)&&(pd))return;//判断
a[i][j]=2;//涂色
for(int k=1;k<=4;k++){
int x=i+bx[k];
int y=j+by[k];
dfs(x,y);//搜索
}
}
int main(){
cin>>n;
for(int i=1;i<=n;i++)
for(int j=1;j<=n;j++)
cin>>a[i][j];
for(int i=1;i<=n;i++)
for(int j=1;j<=n;j++){
dfs(i,j);//深搜方式类似细胞题
}
for(int i=1;i<=n;i++){
for(int j=1;j<=n;j++)
cout<<a[i][j]<<" ";//输出
cout<<endl;
}
return 0;
}
by zheng61 @ 2022-04-07 18:32:45
@[zheng61](/user/415731)
对于样例
```
0 0 0 0 0 0
0 0 1 1 1 1
0 1 1 0 0 1
1 1 0 0 0 1
1 0 0 0 0 1
1 1 1 1 1 1
```
你的程序的结果是:
```
2 2 2 2 2 2
2 2 1 1 1 1
2 1 1 2 2 1
1 1 2 2 2 1
1 2 2 2 2 1
1 1 1 1 1 1
```
by 凤南天 @ 2022-04-07 19:04:53
@[凤南天](/user/437628)
我的是从
```
0 0 0 0 0 0
0 0 1 1 1 1
0 1 1 0 0 1
1 1 0 0 0 1
1 0 0 0 0 1
1 1 1 1 1 1
```
到
```
0 0 0 0 0 0
0 2 1 1 1 1
0 1 1 2 2 1
1 1 2 2 2 1
1 2 2 2 2 1
1 1 1 1 1 1
```
???
by zheng61 @ 2022-04-07 19:09:35
@[zheng61](/user/415731) 你的dfs有问题
by 凤南天 @ 2022-04-07 19:11:47
能帮我改一下吗QAQ
by zheng61 @ 2022-04-07 19:13:57
@[zheng61](/user/415731) ~~我不会~~
by 凤南天 @ 2022-04-07 19:22:39
没人吗QAQ
by zheng61 @ 2022-04-11 18:23:29