Compilare: user.cpp: In function ‘int main()’: user.cpp:52:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v.size();i++) ^ user.cpp:53:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i1=i+1;i1<v.size();i1++) ^ user.cpp:80:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=1;i<vl.size();i++) ^