Package g0501_0600.s0538_convert_bst_to_greater_tree

Class Solution

  • public class Solution
extends Object
    538 - Convert BST to Greater Tree.

    Medium

    Given the root of a Binary Search Tree (BST), convert it to a Greater Tree such that every key of the original BST is changed to the original key plus the sum of all keys greater than the original key in BST.

    As a reminder, a binary search tree is a tree that satisfies these constraints:

    • 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 = [4,1,6,0,2,5,7,null,null,null,3,null,null,null,8]

    Output: [30,36,21,36,35,26,15,null,null,null,33,null,null,null,8]

    Example 2:

    Input: root = [0,null,1]

    Output: [1,null,1]

    Constraints:

    • The number of nodes in the tree is in the range [0, 104].
    • -104 <= Node.val <= 104
    • All the values in the tree are unique.
    • root is guaranteed to be a valid binary search tree.

    Note: This question is the same as 1038: https://leetcode.com/problems/binary-search-tree-to-greater-sum-tree/

    • Constructor Detail

      • Solution

        public Solution()