Compilare: main.cpp: In function 'void insert(trie*, std::string)': main.cpp:68:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 68 | for(int i = 0 ; i < a.size() ; i++) | ~~^~~~~~~~~~ main.cpp: In function 'void solve(std::string)': main.cpp:90:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 90 | for(i = 0 ; i < a.size() ; i++) | ~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:158:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 158 | for(j = 0 ; j < sa[i].size() ; j++) | ~~^~~~~~~~~~~~~~ main.cpp:172:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 172 | for(j = 0 ; j < sb[i].size() ; j++) | ~~^~~~~~~~~~~~~~