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:7:28: 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%d",&a[i][0],&a[i][1]);
                       ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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

{"receive":"2020-08-10T03:46:20.727Z","handle":"2020-08-10T03:46:20.727Z","cache_start":"2020-08-10T03:46:20.735Z","read_cases":"2020-08-10T03:46:20.844Z","judge":"2020-08-10T03:46:20.845Z","done":"2020-08-10T03:46:21.869Z"}