Validate Binary Search Tree Visualizer & Step-by-Step Algorithm Solution

Determine if a binary tree is a valid Binary Search Tree (BST) where every node satisfies min < node.val < max recursively.

Category: trees | Difficulty: Medium

Tags: BST, Binary Search Tree, DFS, Recursion, Range Bounds

Validate Binary Search Tree

2
1
3
100%
state
validRange(-∞, +∞)
isValidtrue
Initialization
1/15
Explanation

Start isValidBST with root: Node(2). Initial range: (-∞, +∞).

Source Code
1function isValidBST(root) {
2 function validate(node, min, max) {
3 if (!node) return true;
4 if (node.val <= min || node.val >= max) return false;
5 return validate(node.left, min, node.val) && validate(node.right, node.val, max);
6 }
7 return validate(root, -Infinity, Infinity);
8}