/in/foo.cc: In function 'int hung()':
/in/foo.cc:37:2: error: 'memset' was not declared in this scope
  memset(linkv, -1, sizeof(linkv));
  ^~~~~~
/in/foo.cc:37:2: note: suggested alternative: 'wmemset'
  memset(linkv, -1, sizeof(linkv));
  ^~~~~~
  wmemset
/in/foo.cc: In function 'int main()':
/in/foo.cc:50:3: error: 'memset' was not declared in this scope
   memset(edge, false, sizeof(edge));
   ^~~~~~
/in/foo.cc:50:3: note: suggested alternative: 'wmemset'
   memset(edge, false, sizeof(edge));
   ^~~~~~
   wmemset