`minn`根本用不着啊，直接广搜，如果搜到了终点就一定是最短路啊
by FCB_1899 @ 2021-03-02 21:58:27
谢谢dalao
~~但是还是0分~~
by B1ade_ @ 2021-03-02 22:04:26
```cpp
#include<bits/stdc++.h>
using namespace std;
bool a[1005][1005];
int x,y,xe,ye,n;
struct node
{
int x,y,d;
};
queue<node>q;
int ne[]={1,0,-1,0},nx[]={0,1,0,-1};
int main()
{
cin>>n;
for (int i=1;i<=n;++i)
{
string st;cin>>st;
for (int j=1;j<=n;++j)
{
a[i][j]=st[j-1]-'0';
}
}
cin>>x>>y>>xe>>ye;
node n11;n11.d=0;n11.x=x;n11.y=y;
q.push(n11);
while (!q.empty())
{
node t=q.front();
q.pop();
if (t.x==xe&&t.y==ye)
{
cout<<t.d;
return 0;
}
for (int i=0;i<4;++i)
{
int xx=t.x+ne[i],yy=t.y+nx[i];
if (xx>=1&&xx<=n&&yy>=1&&yy<=n&&!a[xx][yy])
{
node n12;n12.x=xx;n12.y=yy;n12.d=t.d+1;
q.push(n12);
a[xx][yy]=1;
}
}
}
return 0;
}
```
给你改对了 @[RAINDEER](/user/158878)
by FCB_1899 @ 2021-03-02 22:07:26
~~另外，我认为万能头是一种极劣的癖好~~
by FCB_1899 @ 2021-03-02 22:08:34
@[RAINDEER](/user/158878) ~~不要问怎么写的，代码太古早了。（你看都没有用万能头~~
```cpp
#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<string>
using namespace std;
char c[2010][2010];
int n,x1,y1,x2,y2;bool f=0;
int dx[4]={0,0,-1,1},dy[4]={-1,1,0,0};
int h=0,t=0;
struct st
{
int x;
int y;
int s;
}q[10000010];
void bfs(int a,int b)
{
while (h<t)
{
for (int i=0;i<4;++i)
{
int nx=q[h].x+dx[i];
int ny=q[h].y+dy[i];
if (nx>=1&&nx<=n&&ny>=1&&ny<=n&&c[nx][ny]!='1')
{
if (nx==a&&ny==b) {cout<<q[h].s+1;return ;}
c[nx][ny]='1';
q[t].x=nx;
q[t].y=ny;
q[t++].s=q[h].s+1;
}
}
++h;
}
}
int main()
{
cin>>n;
for (int i=1;i<=n;++i)
for (int j=1;j<=n;++j) cin>>c[i][j];
cin>>x1>>y1>>x2>>y2;
q[t].x=x1;
q[t].s=0;
q[t++].y=y1;
c[x1][y1]='1';
bfs(x2,y2);
return 0;
}
```
by ____OccDreamer @ 2021-03-03 18:30:40
谢谢dalao们
by B1ade_ @ 2021-03-14 21:48:53