foo.cc: In function 'int main()':
foo.cc:34:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&n,&m);
     ~~~~~^~~~~~~~~~~~~~
foo.cc:37:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d",&a[i][j]);
             ~~~~~^~~~~~~~~~~~~~~

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

{"receive":"2020-08-06T09:33:51.919Z","handle":"2020-08-06T09:33:51.919Z","cache_start":"2020-08-06T09:33:51.980Z","read_cases":"2020-08-06T09:33:52.143Z","judge":"2020-08-06T09:33:52.145Z","done":"2020-08-06T09:33:53.067Z"}