0897. Increasing Order Search Tree

https://leetcode.com/problems/increasing-order-search-tree

Description

Given the root of a binary search tree, rearrange the tree in in-order so that the leftmost node in the tree is now the root of the tree, and every node has no left child and only one right child.

Example 1:

**Input:** root = [5,3,6,2,4,null,8,1,null,null,null,7,9]

**Output:** [1,null,2,null,3,null,4,null,5,null,6,null,7,null,8,null,9]

Example 2:

**Input:** root = [5,1,7]

**Output:** [1,null,5,null,7]

Constraints:

• The number of nodes in the given tree will be in the range [1, 100].

• 0 <= Node.val <= 1000

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