Given a binary tree containing digits from `0-9`

only, each root-to-leaf path could represent a number.

An example is the root-to-leaf path `1->2->3`

which represents the number `123`

.

Find the total sum of all root-to-leaf numbers.

**Note:** A leaf is a node with no children.

**Example:**

Input:[1,2,3] 1 / \ 2 3Output:25Explanation:The root-to-leaf path`1->2`

represents the number`12`

. The root-to-leaf path`1->3`

represents the number`13`

. Therefore, sum = 12 + 13 =`25`

.

**Example 2:**

Input:[4,9,0,5,1] 4 / \ 9 0 / \ 5 1Output:1026Explanation:The root-to-leaf path`4->9->5`

represents the number 495. The root-to-leaf path`4->9->1`

represents the number 491. The root-to-leaf path`4->0`

represents the number 40. Therefore, sum = 495 + 491 + 40 =`1026`

.

# Definition for a binary tree node. # class TreeNode: # def __init__(self, x): # self.val = x # self.left = None # self.right = None class Solution: def sumNumbers(self, root: TreeNode) -> int: def getNumbers(root, previous, result): if not root: return current = previous*10 + root.val if not root.left and not root.right: result[0] += current getNumbers(root.left, current, result) getNumbers(root.right, current, result) ans = [0] getNumbers(root, 0, ans) return ans[0]