foo.c: In function 'main':
foo.c:5:11: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'int' [-Wformat=]
   scanf("%d", a);
          ~^
foo.c:6:11: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'int' [-Wformat=]
   scanf("%d", b);
          ~^
foo.c:5:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", a);
   ^~~~~~~~~~~~~~
foo.c:6:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", b);
   ^~~~~~~~~~~~~~
foo.c:5:3: warning: 'a' is used uninitialized in this function [-Wuninitialized]
   scanf("%d", a);
   ^~~~~~~~~~~~~~
foo.c:6:3: warning: 'b' is used uninitialized in this function [-Wuninitialized]
   scanf("%d", b);
   ^~~~~~~~~~~~~~

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

{"receive":"2020-07-13T14:45:58.547Z","handle":"2020-07-13T14:45:58.547Z","cache_start":"2020-07-13T14:45:58.553Z","read_cases":"2020-07-13T14:45:58.677Z","judge":"2020-07-13T14:45:58.680Z","done":"2020-07-13T14:45:58.934Z"}