Compilare: main.cpp: In function 'bool ePer(std::string)': main.cpp:12:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 12 | for(int d = 1; d < s.size(); d++){ | ~~^~~~~~~~~~ main.cpp:16:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 16 | for(int j = 0; j < s.size(); j++){ | ~~^~~~~~~~~~ main.cpp: In function 'void gen()': main.cpp:29:17: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 29 | if(s.size() == n){ | ~~~~~~~~~^~~~