foo.cc: In function 'int main()':
foo.cc:6:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
foo.cc:9:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&a[i]);
   ~~~~~^~~~~~~~~~~~

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

{"receive":"2020-07-28T09:08:15.733Z","handle":"2020-07-28T09:08:15.733Z","cache_start":"2020-07-28T09:08:15.740Z","read_cases":"2020-07-28T09:08:15.932Z","judge":"2020-07-28T09:08:15.938Z","done":"2020-07-28T09:08:16.934Z"}