不写vis数组的危害，本人亲测（（（
@[Algorithm_ZRF](/user/1044048)
by The_Chariot @ 2024-02-01 17:40:24
@[Algorithm_ZRF](/user/1044048) 还有我没看懂你这个BFS，其实这就一BFS板子题，不用那么复杂，读入也正常读入就可以，下附核心代码：
```cpp
queue<node>q;
void bfs()
{
node now,next;
vis[sx][sy]=1;
now.x=sx,now.y=sy,now.step=0;
q.push(now);
while(!q.empty())
{
now=q.front();
q.pop();
for(int i=0;i<4;++i)
{
next.x=now.x+dirx[i],next.y=now.y+diry[i],next.step=now.step+1;
if(next.x==ex&&next.y==ey)
{
ans=next.step;
return ;
}
if(next.x>0&&next.y>0&&next.x<=n&&next.y<=n&&mapp[next.x][next.y]=='0'&&vis[next.x][next.y]==0)
{
vis[next.x][next.y]=1;
q.push(next);
}
}
}
}
```
by The_Chariot @ 2024-02-01 17:47:06
@[The_Chariot](/user/696391) 我用双向BFS做的
by Algorithm_ZRF @ 2024-02-01 18:00:46
@[The_Chariot](/user/696391) 而且mp就是我的vis啊
by Algorithm_ZRF @ 2024-02-01 18:04:18