蒟蒻60分qwq

#include<iostream>
#include<cstdio>
using namespace std;

struct point{
    int x,y,t,father;
}q[404040];

int m,n,sx,sy,ex,ey,ansx[1004],ansy[1004],head,tail,nx,ny;//start x,start y,end x,end y;
int nux[4]={0,1,0,-1},nuy[4]={1,0,-1,0};
bool vis[1004][1004]={0};
char maze[1004][1004];

int main()
{
    cin>>n;
    m=n;
    for(int i=1;i<=m;i++)
        for(int j=1;j<=n;j++)
            cin>>maze[i][j];
    cin>>sx>>sy>>ex>>ey;
    q[1].x=sx;q[1].y=sy;q[1].t=0;q[1].father=0;
    tail++;vis[sx][sy]=1;
    while(head<tail)
    {
        head++;
        for(int i=0;i<4;i++)
        {
            nx=q[head].x+nux[i];
            ny=q[head].y+nuy[i];
            if(!vis[nx][ny] && nx<=m && nx>0 && ny<=n && ny>0 && maze[nx][ny]!='1')
            {   
                tail++;
                q[tail].x=nx;q[tail].y=ny;q[tail].t=q[head].t+1;
                vis[nx][ny]=1;
            }
            if(nx==ex&&ny==ey) 
            {
                cout<<q[tail].t;
                return 0;
            }
        }
    }
    return 0;
}