foo.cc: In function 'int main()':
foo.cc:31:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
foo.cc:33:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &arr[i].u);
   ~~~~~^~~~~~~~~~~~~~~~~
foo.cc:36:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &arr[i].v);
   ~~~~~^~~~~~~~~~~~~~~~~

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

{"receive":"2020-07-11T23:38:41.948Z","handle":"2020-07-11T23:38:41.948Z","cache_start":"2020-07-11T23:38:41.956Z","read_cases":"2020-07-11T23:38:42.152Z","judge":"2020-07-11T23:38:42.155Z","done":"2020-07-11T23:38:42.769Z"}