g0201_0300.s0230_kth_smallest_element_in_a_bst

Class Solution

java.lang.Object

g0201_0300.s0230_kth_smallest_element_in_a_bst.Solution

public class Solution
extends Object

230 - Kth Smallest Element in a BST.

Medium

Given the root of a binary search tree, and an integer k, return the kth smallest value (**1-indexed**) of all the values of the nodes in the tree.

Example 1:

Input: root = [3,1,4,null,2], k = 1

Output: 1

Example 2:

Input: root = [5,3,6,2,4,null,null,1], k = 3

Output: 3

Constraints:

• The number of nodes in the tree is n.
• 1 <= k <= n <= 104
• 0 <= Node.val <= 104

Follow up: If the BST is modified often (i.e., we can do insert and delete operations) and you need to find the kth smallest frequently, how would you optimize?

Constructor Summary

Constructors

Constructor and Description
Solution()

Method Summary

Modifier and Type	Method and Description
int	kthSmallest(TreeNode root, int k)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Solution

public Solution()

Method Detail

kthSmallest

public int kthSmallest(TreeNode root,
                       int k)