foo.cc: In function 'int main()':
foo.cc:120:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
     ~~~~~^~~~~~~~~~~~~~
foo.cc:125:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d",&u,&v);
         ~~~~~^~~~~~~~~~~~~~
foo.cc:131:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%lf",&p);
     ~~~~~^~~~~~~~~~

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

{"receive":"2020-07-08T13:34:08.865Z","handle":"2020-07-08T13:34:08.865Z","cache_start":"2020-07-08T13:34:08.871Z","read_cases":"2020-07-08T13:34:08.995Z","judge":"2020-07-08T13:34:08.996Z","done":"2020-07-08T13:34:10.231Z"}