Compilare: user.cpp: In function ‘void sterge(int)’: user.cpp:19:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[x%key].size();i++) ^ user.cpp: In function ‘void check(int)’: user.cpp:30:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[x%key].size();i++) ^