Compilare: user.cpp: In member function ‘void Trie::insert(std::string, int, int)’: user.cpp:36:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (poz != s.size()) ^ user.cpp:43:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (poz != s.size() && this->fii[index] == NULL) ^ user.cpp:49:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (poz != s.size()) ^ user.cpp: In member function ‘std::string Trie::find(std::string, int)’: user.cpp:91:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (poz != s.size()) ^ user.cpp:104:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (poz == s.size()) ^