/in/foo.cc: In function 'void find(int, int)':
/in/foo.cc:10:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<a[s].size();i++)
               ~^~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:39:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<q.size();i++)
              ~^~~~~~~~~