Compilare: main.cpp: In function 'std::__cxx11::string merge_s(std::__cxx11::string, std::__cxx11::string)': main.cpp:25:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<A.size() && j<B.size()) ~^~~~~~~~~ main.cpp:25:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<A.size() && j<B.size()) ~^~~~~~~~~ main.cpp:28:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(qry(aux)==aux.size()) ~~~~~~~~^~~~~~~~~~~~ main.cpp:39:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(; i<A.size(); i++) ~^~~~~~~~~ main.cpp:41:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(; j<B.size(); j++) ~^~~~~~~~~