Compilare: user.cpp: In member function ‘Node* Trie::insert2(const string&, Node*, int)’: user.cpp:63:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (w.size() - 1 == pos) { ^ user.cpp: In member function ‘std::string Trie::lcp2(const string&, Node*, int)’: user.cpp:77:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos == w.size()) ^ user.cpp: In member function ‘int Trie::count2(const string&, Node*, int)’: user.cpp:93:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos == w.size() - 1) ^ user.cpp: In member function ‘int Trie::count(const string&)’: user.cpp:100:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In member function ‘Node* Trie::del_rec(const string&, Node*, int)’: user.cpp:111:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos == w.size() - 1) { ^