/in/foo.cc: In function 'std::vector<int> Mul(std::vector<int>, int, int)':
/in/foo.cc:8:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < X.size(); i++)
                  ~~^~~~~~~~~~
/in/foo.cc:10:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < X.size(); i++)
                  ~~^~~~~~~~~~
/in/foo.cc:15:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if (i + 1 < X.size())
        ~~~~~~^~~~~~~~~~
/in/foo.cc: In function 'std::vector<int> H(std::vector<int>, std::vector<int>)':
/in/foo.cc:30:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < max(s.size(), in.size()); i++)
                  ~~^~~~~~~~~~~~~~~~~~~~~~~~~~
/in/foo.cc:32:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if (i < min(s.size(), in.size()))
       ~~^~~~~~~~~~~~~~~~~~~~~~~~~~
/in/foo.cc:48:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < out.size(); i++)
                  ~~^~~~~~~~~~~~
/in/foo.cc:52:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if ((i + 1) < out.size())
        ~~~~~~~~^~~~~~~~~~~~