Kth smallest element in BST
Given a binary search tree as a level-order array `arr` (null for missing) and a 1-indexed integer `k`, return the value of the k-th smallest element. The tree is a valid BST with distinct values and `1 <= k <= node count`. `1 <= node count <= 100000`.
Implement
kth_smallest_bst(arr: list[int], k: int) → intExamples
in
[[3,1,4,null,2],1]out1What a strong answer looks like
State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
0:00 of about 20 min
solution.py
InputExpectedGot
[[3,1,4,null,2],1]1not run yetsample