LC 0897 [E] Increasing Order Search Tree - ALawliet/algorithms GitHub Wiki

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def increasingBST(self, root: TreeNode) -> TreeNode:
        self.prev = None
        self.newroot = None
        
        def inorder(node):
            if not node: return
            
            inorder(node.left)
            
            if not self.newroot:
                self.newroot = node
                
            node.left = None
            
            if self.prev:
                self.prev.right = node
                
            self.prev = node
            
            inorder(node.right)
            
        inorder(root)
        return self.newroot