Root equals sum of children

We will check the value of root with the sum of the rest of the tree. If the value of root is equal to the sum of the rest of the tree, then we will return True. Otherwise, we will return False.

# 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

Time complexity: O(1)
Space complexity: O(1)