/in/foo.cc: In function 'std::vector<std::vector<int> > get_map(std::vector<std::vector<int> >)':
/in/foo.cc:10:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0;i < map.size();i++)
                 ~~^~~~~~~~~~~~
/in/foo.cc:12:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int j = 1;j < map[0].size();j++)
                  ~~^~~~~~~~~~~~~~~
/in/foo.cc:17:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 1;i < map.size();i++)
                 ~~^~~~~~~~~~~~
/in/foo.cc:19:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int j = 0;j < map[0].size();j++)
                  ~~^~~~~~~~~~~~~~~