Compilare: user.cpp: In member function ‘void Trie::insert(std::string, int, int)’: user.cpp:39:57: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (this->fii[index] == NULL && i != s.size()) ^ user.cpp:45:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i != s.size()) ^ user.cpp: In member function ‘std::pair<int, std::basic_string<char> > Trie::find(std::string, int)’: user.cpp:76:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i == s.size()) ^