Compilare: main.cpp: In function 'std::string cifre_rem(std::string, int)': 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 i = 0; i < nr.length(); i++) { | ~~^~~~~~~~~~~~~