Class Solution
java.lang.Object
g0001_0100.s0098_validate_binary_search_tree.Solution
98 - Validate Binary Search Tree\.
Medium
Given the `root` of a binary tree, _determine if it is a valid binary search tree (BST)_.
A **valid 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:**

**Input:** root = [2,1,3]
**Output:** true
**Example 2:**

**Input:** root = [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.
**Constraints:**
* The number of nodes in the tree is in the range
[1, 104]
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* -231 <= Node.val <= 231 - 1
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Constructor Summary
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Method Summary
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Constructor Details
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Solution
public Solution()
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Method Details
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isValidBST
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