Leetcode 1079 Solution

This article provides solution to leetcode question 1079 (sum-of-root-to-leaf-binary-numbers)

https://leetcode.com/problems/sum-of-root-to-leaf-binary-numbers

Solution

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

class Solution:
    def sumRootToLeaf(self, root: TreeNode) -> int:
        self.ans = 0

        def dfs(node, val):
            val = 2 * val + node.val

            if not node.left and not node.right:
                self.ans += val
            else:
                if node.left:
                    dfs(node.left, val)
                if node.right:
                    dfs(node.right, val)

        dfs(root, 0)
        return self.ans