foo.cc: In function 'int main()':
foo.cc:10:2: error: 'memset' was not declared in this scope
  memset(a,0,sizeof(a));
  ^~~~~~
foo.cc:10:2: note: suggested alternative: 'wmemset'
  memset(a,0,sizeof(a));
  ^~~~~~
  wmemset

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