foo.cc: In function 'int main()':
foo.cc:62:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
foo.cc:65:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d", &a[i][j]);
    ~~~~~^~~~~~~~~~~~~~~~
foo.cc:68:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d", &b[i][j]);
    ~~~~~^~~~~~~~~~~~~~~~

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

{"receive":"2020-07-13T12:35:53.002Z","handle":"2020-07-13T12:35:53.002Z","cache_start":"2020-07-13T12:35:53.008Z","read_cases":"2020-07-13T12:35:53.133Z","judge":"2020-07-13T12:35:53.140Z","done":"2020-07-13T12:36:13.906Z"}