LeetCode: Construct Binary Tree from Inorder and Postorder Traversal

Given inorder and postorder traversal of a tree, construct the binary tree.
Note:
You may assume that duplicates do not exist in the tree.

Solution:

/**
 * Definition for binary tree
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public TreeNode buildTree(int[] inorder, int[] postorder) {
        return buildTree(inorder, postorder, inorder.length, 0, 0);
    }
    
    public TreeNode buildTree(int[] inOrder, int[] postOrder, int nElements, int startInOrder, int startPostOrder) 
    {
        if (nElements==0)
            return null;
        int rootVal = postOrder[startPostOrder+nElements-1];
        TreeNode root = new TreeNode(rootVal);
        if(nElements==1)
            return root;
        for(int i=0; i<nElements; i++)
        {
            if(inOrder[startInOrder+i]==rootVal)
            {
                root.left =  buildTree(inOrder, postOrder, i, startInOrder, startPostOrder);
                root.right =  buildTree(inOrder, postOrder, nElements-i-1, startInOrder+i+1, startPostOrder+i);
                break;
            }
        }
        return root;
    }
}