foo.cc: In function 'void init(int, int)':
foo.cc:11:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<a[u].size(); i++)
                  ~^~~~~~~~~~~~
foo.cc: In function 'int work(int, int)':
foo.cc:20:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<a[u].size(); i++)
                  ~^~~~~~~~~~~~
foo.cc: In function 'void dfs(int)':
foo.cc:29:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0; i<d[dep].size(); i++)
                  ~^~~~~~~~~~~~~~

自豪的采用 HydroJudger 进行评测(github.com/hydro-dev/HydroJudger)

{"receive":"2020-06-20T13:58:46.502Z","handle":"2020-06-20T13:58:46.502Z","cache_start":"2020-06-20T13:58:46.516Z","read_cases":"2020-06-20T13:58:46.691Z","judge":"2020-06-20T13:58:46.697Z","done":"2020-06-20T13:58:48.113Z"}