foo.cc: In function 'void dfs1(int, int)':
foo.cc:8:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<g[x].size();i++)
              ~^~~~~~~~~~~~
foo.cc: In function 'void dfs2(int, int)':
foo.cc:28:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<g[x].size();i++)
              ~^~~~~~~~~~~~

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

{"receive":"2020-08-12T23:10:04.694Z","handle":"2020-08-12T23:10:04.694Z","cache_start":"2020-08-12T23:10:04.737Z","read_cases":"2020-08-12T23:10:04.961Z","judge":"2020-08-12T23:10:04.973Z","done":"2020-08-12T23:10:07.343Z"}