333. Largest BST Subtree
https://github.com/openset/leetcode/tree/master/problems/largest-bst-subtree
Given a binary tree, find the largest subtree which is a Binary Search Tree (BST), where largest means subtree with largest number of nodes in it.
Note:
A subtree must include all of its descendants.
Example:
Input: [10,5,15,1,8,null,7] 10 / \ 5 15 / \ \ 1 8 7 Output: 3 Explanation: The Largest BST Subtree in this case is the highlighted one. The return value is the subtree's size, which is 3.
Follow up:
Can you figure out ways to solve it with O(n) time complexity?
---
Related problems
---