每个点跑一次bfs......
by __LiChangChao__ @ 2023-06-09 18:18:33
不是每一个点跑一次bfs，从起点开始向外拓展，用数组存储步数，直到无节点可拓展。
like this:
```cpp
//转移
ans[next.x][next.y] = ans[now.x][now.y] + 1;
//主函数
cin >> n >> m >> x >> y;
memset(ans,-1,sizeof ans);
vis[x][y] = 1;
ans[x][y] = 0;
bfs();
for(int i=1;i<=n;i++,printf("\n")){
for(int j=1;j<=m;j++){
printf("%lld ",ans[i][j]);
}
}
```
by Ice_lift @ 2023-06-11 19:44:12
@[qym__xiaobai](/user/857626) 谢谢！
by Washington2022 @ 2023-07-13 00:29:11