Compilare: main.cpp: In function 'int main()': main.cpp:48:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 48 | for (int i = 0; i < s1.size(); i++) { | ~~^~~~~~~~~~~ main.cpp:51:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 51 | if (len == s2.size()) { | ~~~~^~~~~~~~~~~~