#include <iostream> #include <stack> using namespace std; int main() { stack<int> st; int pos = 1; while (pos <= 3) { st.push(pos++); } cout << st.top(); while (pos <= 5) { st.push(pos++); } while (!st.empty()) { cout << st.top(); st.pop(); } return 0; }上述程序的输出为()