@[YZP_AK_IOI](/user/667558)
```
if(vis[nx][ny]==1||mp[nx][ny]==1) continue;
```
要改为
```
if(vis[nx][ny]==1||mp[nx][ny]=='1') continue;
```
因为你 mp 是 char 类型，不是 int。其他见下
by 快斗游鹿 @ 2022-05-04 09:45:01
一点小优化
```
#include<bits/stdc++.h>
using namespace std;
int n,sx,sy,fx,fy;
char mp[1005][1005];
int vis[1005][1005];
int dx[10]={1,0,-1,0};
int dy[10]={0,1,0,-1};
queue<int>qx;
queue<int>qy;
queue<int>step;
int main()
{
int ans=10000000;
cin>>n;
for(int i=1;i<=n;i++)
for(int j=1;j<=n;j++)
cin>>mp[i][j];
cin>>sx>>sy>>fx>>fy;
qx.push(sx);
qy.push(sy);
step.push(0);
while(!qx.empty()&&!qy.empty()&&!step.empty())
{
int x=qx.front();
int y=qy.front();
int st=step.front();
qx.pop();
qy.pop();
step.pop();
if(x==fx&&y==fy){//放在外面判断能优化时间
cout<<st;return 0;
}
for(int i=0;i<4;i++){
int nx=x+dx[i];
int ny=y+dy[i];
if(nx<1||nx>n||ny<1||ny>n) continue;
if(vis[nx][ny]==1||mp[nx][ny]=='1') continue;
qx.push(nx);
qy.push(ny);
step.push(st+1);
vis[nx][ny]=1;
}
}
return 0;
}
```
by 快斗游鹿 @ 2022-05-04 09:47:32
@[快斗游鹿](/user/356925) 谢谢大佬！
by _Kamisato_Ayaka_ @ 2022-05-04 09:52:05