foo.cc: In function 'int main()':
foo.cc:7:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  int n,ans=0;scanf("%d",&n);
                            ^
foo.cc:8:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=1;i<=n;++i) scanf("%d",a+i);
                                       ^

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

{"receive":"2020-04-16T03:45:55.332Z","handle":"2020-04-16T03:45:55.332Z","cache_start":"2020-04-16T03:45:55.339Z","read_cases":"2020-04-16T03:45:55.450Z","judge":"2020-04-16T03:45:55.455Z","done":"2020-04-16T03:45:56.106Z"}