Compilare: main.cpp: In function 'void doZ(std::string&)': main.cpp:11:7: warning: unused variable 'forward' [-Wunused-variable] 11 | bool forward = true; | ^~~~~~~ main.cpp: In function 'int main()': main.cpp:45:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 45 | for (int index = 1; index < str.size(); index++) { | ~~~~~~^~~~~~~~~~~~