/in/foo.cc: In function 'void cal_deep(int, int)':
/in/foo.cc:12:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
      for(int i=0;i<p[x].size();i++)
                  ~^~~~~~~~~~~~
/in/foo.cc: In function 'int remove(int, int)':
/in/foo.cc:21:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int i=0;i<p[x].size();i++)
                ~^~~~~~~~~~~~
/in/foo.cc: In function 'void dfs(int, int)':
/in/foo.cc:30:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<q[layer].size();i++)
                 ~^~~~~~~~~~~~~~~~