Package g0501_0600.s0538_convert_bst_to_greater_tree

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    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 <code>0, 10<sup>4</sup></code>.

    • <code>-10<sup>4</sup><= Node.val <= 10<sup>4</sup></code>

    • 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/

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final TreeNode convertBST(TreeNode root)

      • Methods inherited from class java.lang.Object

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