foo.cc: In function 'int main()':
foo.cc:14:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf ("%d %d", &a, &b);
  ~~~~~~^~~~~~~~~~~~~~~~~

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

{"receive":"2020-07-23T14:16:09.247Z","handle":"2020-07-23T14:16:09.247Z","cache_start":"2020-07-23T14:16:09.253Z","read_cases":"2020-07-23T14:16:09.399Z","judge":"2020-07-23T14:16:09.401Z","done":"2020-07-23T14:16:09.526Z"}