queue_using_stack.cpp

#include <iostream>

using namespace std;

#define SIZE 1000

int stack1[SIZE], stack2[SIZE];
int top1 = -1, top2 = -1;

void push(int data) {
	if (top1 >= SIZE - 1) return;
	stack1[++top1] = data;
}

int pop() {
	if (top2 == -1 && top1 != -1) {
		for (int i = top1; i >= 0; i--) {
			stack2[++top2] = stack1[i];
		}
	}
	return stack2[top2--];
}

int main(void) {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);

	int n;
	cin >> n;
	for (int i = 0; i < n; i++) {
		int x;
		cin >> x;
		push(x);
	}

	for (int i = 0; i < n; i++) {
		cout << pop() << ' ';
	}
	cout << '\n';
	return 0;
}