foo.cc: In function 'int main()':
foo.cc:11:9: error: 'memset' was not declared in this scope
         memset(f,0,sizeof(f));
         ^~~~~~
foo.cc:11:9: note: suggested alternative: 'wmemset'
         memset(f,0,sizeof(f));
         ^~~~~~
         wmemset

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