问题标题: 酷町堂2147，求解决，超时0分

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

const int dir[4][2]{
    {-1,0},{0,-1},{1,0},{0,1}
};

struct coord{
    int x,y;
};

    int N,m;
    int a,b,c,d;

queue<coord>q;

char p[110][110];

bool can(int x,int y){
    if (x>=1&&x<=m&&y>=1&&y<=m) return true;
    return false;
}

bool bfs(int x,int y,int z,int w){
    if (p[x][y]=='d'||p[z][w]=='d') return false;
    q.push((coord){x,y});
    while(!q.empty()){
        coord now=q.front();
        q.pop();
        if (now.x==z&&now.y==w) return true;
        for (int i=0;i<4;i++){
            int nx=now.x+dir[i][0];
            int ny=now.y+dir[i][1];
            if (p[nx][ny]=='s'&&can(nx,ny)){
                q.push((coord){nx,ny});
            }
        }
    }
    return false;
}

int main(){
    cin>>N;
    for (int i=1;i<=N;i++){
        cin>>m;
        for (int j=1;j<=m;j++){
            for (int k=1;k<=m;k++){
                cin>>p[j][k];
            }
        }
        cin>>a>>b>>c>>d;
        if (bfs(a,b,c,d)) cout<<"YES"<<endl;
        else cout<<"NO"<<endl;
    }
    return 0;
}