foo.cc: In function 'int main()':
foo.cc:120:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~~
foo.cc:123:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &coordin[i][1], &coordin[i][2]);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:127:8: 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)

{"receive":"2020-07-29T12:50:12.610Z","handle":"2020-07-29T12:50:12.610Z","cache_start":"2020-07-29T12:50:12.616Z","read_cases":"2020-07-29T12:50:12.752Z","judge":"2020-07-29T12:50:12.753Z","done":"2020-07-29T12:50:13.166Z"}