package Others;

/* Program to reverse a Stack using Recursion*/

import java.util.Stack;

public class ReverseStackUsingRecursion {

 // Stack
 private static Stack<Integer> stack = new Stack<>();

 // Main function
 public static void main(String[] args) {
 // To Create a Dummy Stack containing integers from 0-9
 for (int i = 0; i < 10; i++) {
 stack.push(i);
 }
 System.out.println("STACK");

 // To print that dummy Stack
 for (int k = 9; k >= 0; k--) {
 System.out.println(k);
 }

 // Reverse Function called
 reverseUsingRecursion(stack);

 System.out.println("REVERSED STACK : ");
 // To print reversed stack
 while (!stack.isEmpty()) {
 System.out.println(stack.pop());
 }
 }

 // Function Used to reverse Stack Using Recursion
 private static void reverseUsingRecursion(Stack<Integer> stack) {
 if (stack.isEmpty()) // If stack is empty then return
 {
 return;
 }
 /* All items are stored in call stack until we reach the end*/

 int temptop = stack.peek();
 stack.pop();
 reverseUsingRecursion(stack); // Recursion call
 insertAtEnd(temptop); // Insert items held in call stack one by one into stack
 }

 // Function used to insert element at the end of stack
 private static void insertAtEnd(int temptop) {
 if (stack.isEmpty()) {
 stack.push(temptop); // If stack is empty push the element
 } else {
 int temp = stack.peek(); /* All the items are stored in call stack until we reach end*/
 stack.pop();

 insertAtEnd(temptop); // Recursive call

 stack.push(temp);
 }
 }
}