LeetCode——700. Search in Binary Search Tree

Title description:

Given the root node of the binary search tree (BST) and a value. You need to find a node in the BST that has a node value equal to a given value. Returns the subtree rooted at this node. If the node does not exist, NULL is returned.

For example,
given a binary search tree:

    4
   / \
  2   7
 / \
1   3

Sum value: 2
You should return the following subtree:

  2     
 / \   
1   3

In the above example, if the value we are looking for is 5, but because there is no node with a value of 5, we should return NULL.

code show as below:

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
class Solution {
    
    
  public TreeNode searchBST(TreeNode root, int val) {
    
    
    while (root != null && val != root.val)
        root = val < root.val ? root.left : root.right;
        return root;
    }
}

Results of the: