Compilare: main.cpp: In function 'trie* insert(trie*, std::string)': main.cpp:22:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 22 | for( i = 0; i < s.size(); i++ ){ | ~~^~~~~~~~~~ main.cpp: In function 'void solve(trie*, std::string)': main.cpp:34:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 34 | for( i = 0; i < s.size(); i++ ){ | ~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:86:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::__cxx11::basic_string<char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 86 | for( i = 0; i < v.size(); i++ ){ | ~~^~~~~~~~~~