Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:20:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if( V.size() < (1<<l) ){ // am una sau mai multe lipsa ^ user.cpp:25:25: error: ‘aux’ was not declared in this scope aux.append("b"); ^ user.cpp:27:25: error: ‘aux’ was not declared in this scope aux.append("a"); ^ user.cpp:29:27: error: ‘aux’ was not declared in this scope if(V.find(aux)==V.end()){ ^