/in/foo.cc: In function 'int main()':
/in/foo.cc:20:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<vvec.size();i++)
                 ~^~~~~~~~~~~~
/in/foo.cc:64:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if(index>=s.size())
            ~~~~~^~~~~~~~~~
/in/foo.cc:32:13: warning: unused variable 'copy_sc' [-Wunused-variable]
         int copy_sc=cnt;
             ^~~~~~~