foo.cc: In function 'int main()':
foo.cc:82:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
foo.cc:83:41: 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]),b[i]=a[i];
                        ~~~~~~~~~~~~~~~~~^~~~~~~~~~

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

{"receive":"2020-05-23T04:06:19.451Z","handle":"2020-05-23T04:06:19.451Z","cache_start":"2020-05-23T04:06:19.458Z","read_cases":"2020-05-23T04:06:20.712Z","judge":"2020-05-23T04:06:20.712Z","done":"2020-05-23T04:06:22.036Z"}