foo.cc: In function 'int main()':
foo.cc:44:20: warning: statement has no effect [-Wunused-value]
             a[i][j]=='#';
             ~~~~~~~^~~~~
foo.cc: In function 'int BFS()':
foo.cc:38:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

[Hydro](https://hydro.ac)提供评测服务