foo.cc: In function 'int main()':
foo.cc:13:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  freopen("隐形的翅膀.in","r",stdin);
  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:14:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
foo.cc:16:8: 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":"2020-07-25T02:47:26.331Z","handle":"2020-07-25T02:47:26.331Z","cache_start":"2020-07-25T02:47:26.342Z","read_cases":"2020-07-25T02:47:26.542Z","judge":"2020-07-25T02:47:26.544Z","done":"2020-07-25T02:47:27.419Z"}