/in/foo.cc: In function 'int main()':
/in/foo.cc:17:9: error: 'a' was not declared in this scope
  memset(a,0,sizeof(a));
         ^
/in/foo.cc:18:9: error: 'ans' was not declared in this scope
  memset(ans,0,sizeof(ans));
         ^~~
/in/foo.cc:19:13: error: 't' was not declared in this scope
  while(cin>>t);
             ^