998-maximum-binary-tree.py

"""
We are given the root node of a maximum tree: a tree where every node has a value greater than any other value in its subtree.
Just as in the previous problem, the given tree was constructed from an list A (root = Construct(A)) recursively with the following Construct(A) routine:
If A is empty, return null.
Otherwise, let A[i] be the largest element of A.  Create a root node with value A[i].
The left child of root will be Construct([A[0], A[1], ..., A[i-1]])
The right child of root will be Construct([A[i+1], A[i+2], ..., A[A.length - 1]])
Return root.
Note that we were not given A directly, only a root node root = Construct(A).
Suppose B is a copy of A with the value val appended to it.  It is guaranteed that B has unique values.
Return Construct(B).

Example:

Input: root = [4,1,3,null,null,2], val = 5
Output: [5,4,null,1,3,null,null,2]
Explanation: A = [1,4,2,3], B = [1,4,2,3,5]
"""


# Definition for a binary tree node.
class TreeNode:
    def __init__(self, x):
        self.val = x
        self.left = None
        self.right = None


class Solution:
    def insertIntoMaxTree(self, root: TreeNode, val: int) -> TreeNode:
        new_node = TreeNode(val)
        if root.val < val:
            new_node.left = root
            return new_node
        node = root
        added = False
        while node.right:
            if node.right.val < val:
                new_node.left = node.right
                break
            node = node.right
        node.right = new_node
        return root