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 < s1.length(); i++) | ~~^~~~~~~~~~~~~ main.cpp:37:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 37 | for (int i = 0; i < s1.length(); i++) | ~~^~~~~~~~~~~~~ main.cpp:48:31: 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 = s1.length(); i < s2.length(); i++) | ~~^~~~~~~~~~~~~