Compilare: user.cpp: In function ‘Trie* add(Trie*, int)’: user.cpp:34:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (p == s.size()) return node; ^ user.cpp: In function ‘void makePhi()’: user.cpp:63:48: warning: array subscript has type ‘char’ [-Wchar-subscripts] while (crt != root && crt -> son[ch] == NULL) ^ user.cpp:65:30: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (crt -> son[ch] != NULL) crt = crt -> son[ch]; ^ user.cpp:65:60: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (crt -> son[ch] != NULL) crt = crt -> son[ch]; ^ user.cpp: In function ‘void makeSol()’: user.cpp:78:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sir.size(); ++i) ^ user.cpp:81:46: warning: array subscript has type ‘char’ [-Wchar-subscripts] while (node != root && node -> son[ch] == NULL) ^ user.cpp:83:27: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (node -> son[ch] != NULL) node = node -> son[ch]; ^ user.cpp:83:59: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (node -> son[ch] != NULL) node = node -> son[ch]; ^