/in/foo.cc: In function 'int main()':
/in/foo.cc:10:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < word.length(); i++) {
                  ~~^~~~~~~~~~~~~~~
/in/foo.cc:12:8: warning: array subscript has type 'char' [-Wchar-subscripts]
   map[c]++;
        ^