Preorder to Postorder Java

PROGRAM TO FIND POSTORDER TRAVERSAL OF BST FROM PREORDER TRAVERSAL

import java.io.*;

 

class MAIN {

     

    public void getPostOrderBST(int pre[])

    {

        int pivotPoint = 0;

       

        // run loop from 1 to length of pre

        for (int i = 1; i < pre.length; i++)

        {

            if (pre[0] <= pre[i])

            {

                pivotPoint = i;

                break;

            }

        }

       

        // print from pivot length -1 to zero

        for (int i = pivotPoint - 1; i > 0; i--)

        {

            System.out.print(pre[i] + " ");

        }

       

        // print from end to pivot length

        for (int i = pre.length - 1; i >= pivotPoint; i--)

        {

            System.out.print(pre[i] + " ");

        }

        System.out.print(pre[0]);

    }

   

    // Driver Code

    public static void main(String[] args)

    {

        GFG obj = new GFG();

        int pre[] = { 40, 30, 32, 35, 80, 90, 100, 120 };

        obj.getPostOrderBST(pre);

    }

}

OUTPUT:

35 32 30 120 100 90 80 40

CREDITS: https://www.geeksforgeeks.org/find-postorder-traversal-of-bst-from-preorder-traversal/