LeetCode 98. Validate Binary Search Tree [Algorithm + Code Explained ] Best Solution

One of the most frequently asked coding interview questions on Trees in companies like Google, Facebook, Amazon, LinkedIn, Microsoft, Uber, Apple, Adobe etc. LeetCode : Validate Binary Search Tree Question : Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only nodes with keys less than the node's key. The right subtree of a node contains only nodes with keys greater than the node's key. Both the left and right subtrees must also be binary search trees. Example 1: 2 / \ 1 3 Input: [2,1,3] Output: true Example 2: 5 / \ 1 4 / \ 3 6 Input: [5,1,4,null,null,3,6] Output: false Explanation: The root node's value is 5 but its right child's value is 4. Connect with me on LinkedIn at: https://www.linkedin.com/in/jayati-tiwari/