Sum Root to Leaf Numbers
You are given the root of a binary tree containing digits from 0 to 9 only.
Each root-to-leaf path in the tree represents a number.
- For example, the root-to-leaf path
1 -> 2 -> 3represents the number123.
Return the total sum of all root-to-leaf numbers. Test cases are generated so that the answer will fit in a 32-bit integer.
A leaf node is a node with no children.
Example 1:
Input: root = [1,5,1,null,null,null,6]
Output: 131Explanation:
The root to leaf path 1 -> 5 represents the number 15.
The root to leaf path 1 -> 1 -> 6 represents the number 116.
The sum of both the numbers is: 15 + 116 = 131.
Example 2:
Input: root = [1,2,1,9,2,3,4]
Output: 478Explanation:
The root to leaf path 1 -> 2 -> 9 represents the number 129.
The root to leaf path 1 -> 2 -> 2 represents the number 122.
The root to leaf path 1 -> 1 -> 3 represents the number 113.
The root to leaf path 1 -> 1 -> 4 represents the number 114.
The sum the numbers is: 129 + 122 + 113 + 114 = 478.
Constraints:
1 <= number of nodes in the tree <= 10000 <= Node.val <= 9- The depth of the tree will not exceed
10.