/in/foo.cc: In function 'int main()':
/in/foo.cc:34:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 1; i < s.size(); i++)
                 ~~^~~~~~~~~~
/in/foo.cc:36:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j = i; j < s.size(); j++)
                  ~~^~~~~~~~~~
/in/foo.cc:46:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
      for(int jj = 0; jj < d[it].size(); jj++)
                      ~~~^~~~~~~~~~~~~~
/in/foo.cc:66:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 1; i < s.size(); i++)
                  ~~^~~~~~~~~~