Compilare: user.cpp: In function ‘void Make_Prime_Powers()’: user.cpp:30:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < V.size(); i++) ^ user.cpp: In function ‘void Back1(int, int)’: user.cpp:83:49: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = sol[k - 1] + 1; i < V.size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:105:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < S.size(); i++) ^