#230

Kth Smallest Element in a BST

medium· Treesruns: 0

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

wpm 0acc 100%time 0:000 / 394

class Solution:
    def kthSmallest(self, root: TreeNode | None, k: int) -> int:
        stack = []
        curr = root
        while curr or stack:
            while curr:
                stack.append(curr)
                curr = curr.left
            curr = stack.pop()
            k -= 1
            if k == 0:
                return curr.val
            curr = curr.right
        return -1

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