Compilare: main.cpp: In function 'int main()': main.cpp:26:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 26 | for(int i = 0;i < a.size(); ++i) k += b[i]; | ~~^~~~~~~~~~ main.cpp:28:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 28 | for(int i = a.size();i < b.size(); ++i) | ~~^~~~~~~~~~ main.cpp:35:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 35 | for(int i = 0;i < pz.size(); ++i) cout << pz[i] << ' '; | ~~^~~~~~~~~~~