foo.cc: In function 'void dfs(int, int)':
foo.cc:9:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<v[p][k].size();i++)dfs(v[p][k][i],p);
              ~^~~~~~~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:14:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);
  ~~~~~^~~~~~~~~~~~~~
foo.cc:16:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&x,&y);
   ~~~~~^~~~~~~~~~~~~~

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

正在同步测试数据，请稍后
{"receive":"2020-08-10T03:16:20.110Z","handle":"2020-08-10T03:16:20.110Z","cache_start":"2020-08-10T03:16:20.119Z","read_cases":"2020-08-10T03:16:21.378Z","judge":"2020-08-10T03:16:21.378Z","done":"2020-08-10T03:16:22.703Z"}