Kth Smallest Element in a BST
CodingPhone Screen, OnsiteSoftware EngineerReported Mar, 2026
Examples
Example 1:
Input: root = [2,1,3], k = 1
Output: 1
Example 2:
Input: root = [4,3,5,2,null], k = 4
Output: 5
Example 1:
Input: root = [2,1,3], k = 1
Output: 1
Example 2:
Input: root = [4,3,5,2,null], k = 4
Output: 5
Given the root of a binary search tree, and an integer k, return the kth smallest value (1-indexed) in the tree.
A binary search tree satisfies the following constraints:
1 <= k <= The number of nodes in the tree <= 10000 <= Node.val <= 1000Interview note: A common follow-up asks for a solution with O(1) extra space.