2025-08-02 05:55:10 +0000 UTC

# 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 sumRootToLeaf(self, root: Optional[TreeNode]) -> int:
        res = 0
        queue = [(root, 0)]
        while queue:
            node, parent = queue.pop()
            if node is None:
                continue
            val = (parent << 1) | node.val
            if not node.left and not node.right:
                res += val
            queue.extend(((node.left, val), (node.right, val)))
        return res