foo.c:3:5: warning: conflicting types for built-in function 'pow' [-Wbuiltin-declaration-mismatch]
 int pow(int x,int n)
     ^~~
foo.c:27:6: warning: return type of 'main' is not 'int' [-Wmain]
 void main()
      ^~~~
foo.c: In function 'main':
foo.c:34:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &a);
  ^~~~~~~~~~~~~~~
foo.c:36:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ^~~~~~~~~~~~~~~

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

{"receive":"2020-07-15T17:08:12.267Z","handle":"2020-07-15T17:08:12.267Z","cache_start":"2020-07-15T17:08:12.271Z","read_cases":"2020-07-15T17:08:12.382Z","judge":"2020-07-15T17:08:12.383Z","done":"2020-07-15T17:08:12.463Z"}