g1301_1400.s1373_maximum_sum_bst_in_binary_tree

Class Solution

java.lang.Object

g1301_1400.s1373_maximum_sum_bst_in_binary_tree.Solution

public class Solution
extends Object

1373 - Maximum Sum BST in Binary Tree.

Hard

Given a binary tree root, return the maximum sum of all keys of any sub-tree which is also a 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:

Input: root = [1,4,3,2,4,2,5,null,null,null,null,null,null,4,6]

Output: 20

Explanation: Maximum sum in a valid Binary search tree is obtained in root node with key equal to 3.

Example 2:

Input: root = [4,3,null,1,2]

Output: 2

Explanation: Maximum sum in a valid Binary search tree is obtained in a single root node with key equal to 2.

Example 3:

Input: root = [-4,-2,-5]

Output: 0

Explanation: All values are negatives. Return an empty BST.

Constraints:

• The number of nodes in the tree is in the range [1, 4 * 104].
• -4 * 104 <= Node.val <= 4 * 104

Constructor Summary

Constructors

Constructor and Description
Solution()

Method Summary

Modifier and Type	Method and Description
int	maxSumBST(TreeNode root)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Solution

public Solution()

Method Detail

maxSumBST

public int maxSumBST(TreeNode root)