Compilare: user.cpp: In member function ‘void Trie::insert(const string&)’: user.cpp:79:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (; i < w.size(); i++) { ^ user.cpp: In member function ‘std::string Trie::lcp(const string&)’: user.cpp:97:13: warning: statement has no effect [-Wunused-value] for (i; i < w.size(); i++) { ^ user.cpp:97:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i; i < w.size(); i++) { ^ user.cpp: In member function ‘int Trie::count(const string&)’: user.cpp:111:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < w.size(); i++) { ^ user.cpp: In member function ‘Node* Trie::del_rec(const string&, Node*, int)’: user.cpp:124:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos == w.size()) { ^ user.cpp: In function ‘int main()’: user.cpp:116:32: warning: ‘i’ may be used uninitialized in this function [-Wmaybe-uninitialized] return crt->get_count(w[i]); ^ user.cpp:110:11: note: ‘i’ was declared here int i; ^