Root Equals Sum of Children — LeetCode 2236 Python Solution

The problem

You are given the root of a binary tree that consists of exactly 3 nodes: the root, its left child, and its right child. Return true if the value of the root is equal to the sum of the values of its two children, or false otherwise.

Example

Input

root = [10,4,6]

Output

true

Explanation

The values of the root, its left child, and its right child are 10, 4, and 6, respectively.

Python solution

# 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 checkTree(self, root: Optional[TreeNode]) -> bool:
        return root.val == root.left.val + root.right.val

Complexity

Pattern: Tree Traversal

Choose the order — preorder, inorder, postorder, level — and the problem solves itself. LeetCode 2236. Root Equals Sum of Children is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Tree and Binary Tree.

The tree traversal guide has the Python template for the pattern and the 225 LeetCode problems that use it.

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