Validate binary search tree
Given a binary tree as a level-order array (null for missing), determine whether it is a valid binary search tree: every node's value is strictly greater than all values in its left subtree and strictly less than all values in its right subtree. Duplicate values make it invalid. Return true or false.
Implement
is_valid_bst(level: list) → boolExamples
in
[[2,1,3]]outtrueWhat 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 16 min
solution.py
InputExpectedGot
[[2,1,3]]truenot run yetsample