Compilare: user.cpp: In function ‘int main()’: user.cpp:35:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=1;i<V.size();i++) ^ user.cpp:45:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<V.size(); i++) { ^ user.cpp:61:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=2;i<V.size(); i++) { ^