Compilare: main.cpp: In function 'bool check(std::__cxx11::string, std::__cxx11::string)': main.cpp:37:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<a.length(); i++) ~^~~~~~~~~~~ main.cpp:44:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (j == b.length()) ~~^~~~~~~~~~~~~ main.cpp: In function 'bool compara(element&, element&)': main.cpp:32:1: warning: control reaches end of non-void function [-Wreturn-type] } ^