/* Java Program to implement a stack using two queue */
import java.util.*;
class Stack_using_Queue {
static class Stack {
// Two inbuilt queues
static Queue q1 = new LinkedList();
static Queue q2 = new LinkedList();
// To maintain current number of elements
static int size;
Stack()
{
size = 0;
}
static void push(int x)
{
size++;
// Push x first in empty q2
q2.add(x);
// Push all the remaining
// elements in q1 to q2.
while (!q1.isEmpty()) {
q2.add(q1.peek());
q1.remove();
}
// swap the names of two queues
Queue q = q1;
q1 = q2;
q2 = q;
}
static void pop()
{
// if no elements are there in q1
if (q1.isEmpty())
return;
q1.remove();
size--;
}
static int top()
{
if (q1.isEmpty())
return -1;
return q1.peek();
}
static int size()
{
return size;
}
}
// driver code
public static void main(String[] args)
{
Scanner sc = new Scanner(System.in);
Stack s = new Stack();
System.out.println("Enter the limit");
int n = sc.nextInt();
//accepting input from user
for(int i = 1; i <= n; i++)
s.push(i);
//printing the output
for(int i = 1; i <= n; i++){
System.out.println(s.top());
s.pop();
}
}
}
/* Time Complexity : O(n)
Space Complexity : O(n)
Input
5
Output
5
4
3
2
1
*/