Compilare: user.cpp: In function ‘int main()’: user.cpp:41:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<h.size(); i++) ^ user.cpp:50:16: warning: ‘x’ may be used uninitialized in this function [-Wmaybe-uninitialized] a[x].clear(); ^ user.cpp:48:19: warning: ‘poz’ may be used uninitialized in this function [-Wmaybe-uninitialized] swap(h[poz], h[h.size()-1]); h.pop_back(); ^