/in/foo.cc: In member function 'void Trie::Insert(std::__cxx11::string)':
/in/foo.cc:28:27: warning: array subscript has type 'char' [-Wchar-subscripts]
    if (current->children[c] == NULL)
                           ^
/in/foo.cc:30:24: warning: array subscript has type 'char' [-Wchar-subscripts]
     current->children[c] = new TrieNode;
                        ^
/in/foo.cc:31:24: warning: array subscript has type 'char' [-Wchar-subscripts]
     current->children[c]->ch = ch;
                        ^
/in/foo.cc:34:33: warning: array subscript has type 'char' [-Wchar-subscripts]
    current = current->children[c];
                                 ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:106:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 1; i < T.size(); i++)
                  ~~^~~~~~~~~~