/in/foo.cc: In function 'int main()':
/in/foo.cc:14:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < arr.size(); i++)
                  ~~^~~~~~~~~~~~
/in/foo.cc:24:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   while (loc >= arr.size())
          ~~~~^~~~~~~~~~~~~