Compilare: user.cpp: In function ‘int main()’: user.cpp:18:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < a.size(); cin >> a[i++] ); ^ user.cpp:21:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < a.size(); i++) ^ user.cpp:34:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (y > a.size() / 2) cout << x[0] << ' ' << y; ^