救命！！！！！！！！输入有问题

#include<iostream> 
#include<queue>
using namespace std;
// bfs
int step[1050][1050],flag[1050][1050],n,x1,y1,x2,y2;
struct point{
    int x;
    int y;
};
const int k[4][2]={{1,0},{-1,0},{0,1},{0,-1}};
queue<point>Q;
bool cmp(int x,int y){
    if(flag[x][y]==1) return 0;
    if(step[x][y]>0) return 0;
    if(x<1||x>n) return 0;
    if(y<1||y>n) return 0;
    return 1;
}
int main(){
    cin>>n;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            cin>>flag[i][j];
        }
    }
    cin>>x1>>y1>>x2>>y2;
    Q.push((point){x1,y1});
    while(!Q.empty()){
        point now=Q.front();
        Q.pop();
        int nowx=now.x,nowy=now.y;
        for(int i=0;i<4;i++){
            int nx=nowx+k[i][0];
            int ny=nowy+k[i][1];
            if(cmp(nx,ny)){
                step[nx][ny]=step[nowx][nowy]+1;
                Q.push((point){nx,ny});
            }
        }
    }
    cout<<step[x2][y2];
    return 0;
}