Compilare: main.cpp: In member function 'void Trie::Insert(std::__cxx11::string)': main.cpp:28:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.size(); ++i) { ~~^~~~~~~~~~ main.cpp:30:27: warning: array subscript has type 'char' [-Wchar-subscripts] if(curr->nxt[c] == 0) { ^ main.cpp:32:28: warning: array subscript has type 'char' [-Wchar-subscripts] curr->nxt[c] = new Node(); ^ main.cpp:34:31: warning: array subscript has type 'char' [-Wchar-subscripts] curr = curr->nxt[c]; ^ main.cpp:35:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i == s.size() - 1) { ~~^~~~~~~~~~~~~~~ main.cpp: In member function 'void Trie::Count(int, int, std::__cxx11::string)': main.cpp:54:27: warning: array subscript has type 'char' [-Wchar-subscripts] if(curr->nxt[c] != 0) { ^ main.cpp:55:35: warning: array subscript has type 'char' [-Wchar-subscripts] curr = curr->nxt[c]; ^ main.cpp: In function 'int main()': main.cpp:91:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.size(); ++i) { ~~^~~~~~~~~~