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, and every node has no left child and only one right child.
Examples
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]Explanation:
In-order right-skewed.
Input:
root = [4,2,6,1,3,5,7]Output:
[1,null,2,null,3,null,4,null,5,null,6,null,7]Explanation:
Perfect binary search tree converted to right-skewed tree. In-order traversal visits nodes 1,2,3,4,5,6,7, so each node becomes the right child of the previous node in sequence.
Input:
root = [10,5,15,null,8,12,20]Output:
[5,null,8,null,10,null,12,null,15,null,20]Explanation:
BST with missing left subtree at node 5. In-order traversal gives 5,8,10,12,15,20, creating a right-skewed tree where each node points to the next larger value as its right child.
Constraints
- •
1 ≤ nodes ≤ 100