Compilare: main.cpp: In function 'int calc(std::string&, std::string&, int, int)': main.cpp:22:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 22 | if (l1 == a.size() || l2 == a.size()) | ~~~^~~~~~~~~~~ main.cpp:22:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 22 | if (l1 == a.size() || l2 == a.size()) | ~~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:49:21: 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] 49 | for (int i = 1; i < v.size(); ++i) | ~~^~~~~~~~~~ main.cpp:59:21: 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] 59 | for (int i = 0; i < v.size(); ++i) { | ~~^~~~~~~~~~