Compilare: user.cpp: In function ‘void multiply(int)’: user.cpp:14:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i < V.size() || t) { ^ user.cpp:15:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i < V.size()) t = t + V[i] * k; ^ user.cpp: In function ‘int main()’: user.cpp:37:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i == V.size() - 1) out << V[i]; ^