首发！！！！！

太简单了

（其实肝了很久。。。）

#include <bits/stdc++.h> 
using namespace std;
int n,sx,sy,tx,ty,vis[1100][1100];
char a[1100][1100]={};
int d[1100][1100];
void bfs(int x,int y){
    d[x][y]=0;
    queue <int>xq,yq;
    xq.push(x);yq.push(y);
    while(!xq.empty()&&!yq.empty()){
        if(xq.front()==tx&&yq.front()==ty)return;
        int xn=xq.front(),yn=yq.front();
        if(!vis[xn][yn]&&a[xn][yn]!='1'){
            vis[xn][yn]=1;               
            if(xn+1<=n){xq.push(xn+1);yq.push(yn);d[xn+1][yn]=d[xn][yn]+1;}
            if(xn-1>=1){xq.push(xn-1);yq.push(yn);d[xn-1][yn]=d[xn][yn]+1;}
            if(yn+1<=n){xq.push(xn);yq.push(yn+1);d[xn][yn+1]=d[xn][yn]+1;}
            if(yn-1>=1){xq.push(xn);yq.push(yn-1);d[xn][yn-1]=d[xn][yn]+1;}
        }
        xq.pop();yq.pop();
    }
}
int main(){
    cin>>n;
    for(int i=1;i<=n;i++)for(int j=1;j<=n;j++){cin>>a[i][j];}
    cin>>sx>>sy>>tx>>ty;
    bfs(sx,sy);
    cout<<d[tx][ty]<<endl;
    return 0;
}