Compilare: main.cpp: In function 'void add(Trie*, const string&, int)': main.cpp:20:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'unsigned int'} [-Wsign-compare] 20 | if (idx == s.size()) { | ~~~~^~~~~~~~~~~ main.cpp: In function 'bool checkPref(Trie*, const string&, int)': main.cpp:32:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'unsigned int'} [-Wsign-compare] 32 | if (idx == s.size()) | ~~~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:84:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'unsigned int'} [-Wsign-compare] 84 | for (int i = 0; i < x.size(); ++i) { | ~~^~~~~~~~~~ main.cpp:88:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'unsigned int'} [-Wsign-compare] 88 | if (i < x.size() - 1) | ~~^~~~~~~~~~~~~~