Compilare: main.cpp: In function 'int main()': main.cpp:18:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'unsigned int'} [-Wsign-compare] 18 | for (int i = 0; i < s1.size(); i++) { | ~~^~~~~~~~~~~ main.cpp:25:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'unsigned int'} [-Wsign-compare] 25 | for (int i = s1.size(); i < s2.size(); i++) { | ~~^~~~~~~~~~~