/in/foo.cc: In function 'int main()':
/in/foo.cc:9:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<s.size();i++)
              ~^~~~~~~~~
/in/foo.cc:65:13: warning: 'cnt' may be used uninitialized in this function [-Wmaybe-uninitialized]
    last[cnt]=h[i];
    ~~~~~~~~~^~~~~