Problem: Validate Binary Search Tree
Explore how to validate a binary search tree by recursively checking if each node's value fits within bounded constraints set by its ancestors. Understand the recursive approach to ensure the BST properties hold throughout the tree, and learn to implement an efficient solution with O(n) time complexity.
We'll cover the following...
Statement
Given the root of a binary tree, determine whether it is a valid binary search tree (BST).
A valid BST satisfies the following properties:
The left subtree of every node contains only nodes with keys strictly less than that node’s key.
The right subtree of every node contains only nodes with keys strictly greater than that node’s key.
Both the left and right subtrees must themselves be valid binary search trees.
Return true if the given binary tree is a valid BST, and false otherwise.
Constraints:
The number of nodes in the tree is in the range
. ...