foo.cc: In function 'int main()':
foo.cc:7:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
foo.cc:9:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&a[i]);
    ~~~~~^~~~~~~~~~~~
foo.cc:10:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&b);
  ~~~~~^~~~~~~~~

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

{"receive":"2020-07-10T07:26:57.865Z","handle":"2020-07-10T07:26:57.865Z","cache_start":"2020-07-10T07:26:57.871Z","read_cases":"2020-07-10T07:26:57.994Z","judge":"2020-07-10T07:26:57.995Z","done":"2020-07-10T07:26:59.190Z"}