Compilare: main.cpp: In function 'int main()': main.cpp:17:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 17 | for (int j = 0; j < sir.length(); j++) | ~~^~~~~~~~~~~~~~ main.cpp:21:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 21 | for (int i = j; i < sir.length(); i++) { | ~~^~~~~~~~~~~~~~