模板

#include<bits/stdc++.h>
using namespace std;
struct node{
    int x,y;
};
int n,m,fx,fy;
char mp[45][45];
int dir[4][2] = {{0,-1},{0,1},{-1,0},{1,0}};
bool vis[45][45];
bool check(int x,int y){
    return x >= 1 && y >= 1 && x <= n && y <= m && vis[x][y] == false && mp[x][y] == '.';
}
void bfs(int x,int y){
    queue<node> q;
    q.push({x,y});
    vis[x][y] = true;
    while(!q.empty()){
        node f = q.front();
        q.pop();
        if(f.x == fx && f.y == fy){
            cout << "YES";
            return;
        }
        for(int i = 0;i < 4;i++){
            int nx = f.x + dir[i][0],ny = f.y + dir[i][1];
            if(check(nx,ny)){
                vis[nx][ny] = true;
                q.push({nx,ny});
            }
        }
    }
    cout << "NO";
}
int main(){
    cin >> n >> m;
    int sx,sy; cin >> sx >> sy;
    cin >> fx >> fy;
    for(int i = 1;i <= n;i++){
        for(int j = 1;j <= m;j++) cin >> mp[i][j];
    }
    bfs(sx,sy);
    return 0;
}