foo.cc: In function 'void BFS()':
foo.cc:24:7: warning: unused variable 'ns' [-Wunused-variable]
   24 |   int ns = 0;
      |       ^~
foo.cc: In function 'int main()':
foo.cc:51:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   51 |  scanf("%d%d",&n,&m);
      |  ~~~~~^~~~~~~~~~~~~~
foo.cc:54:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   54 |    scanf("%d",&map_[i][j]);
      |    ~~~~~^~~~~~~~~~~~~~~~~~
foo.cc:57:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   57 |  scanf("%d%d%d%d",&frx,&fry,&tox,&toy);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

正在同步测试数据，请稍后
[Hydro](https://hydro.ac)提供评测服务