Compilare: main.cpp: In function 'bool query(std::__cxx11::string&)': main.cpp:16:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return (x == output.size()); ~~^~~~~~~~~~~~~~~~ main.cpp: In function 'std::__cxx11::string solve(int, int)': main.cpp:24:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(ok == true && s.size() < n) { ~~~~~~~~~^~~