Package g0101_0200.s0129_sum_root_to_leaf_numbers

Class Solution

  • public class Solution
extends Object
    129 - Sum Root to Leaf Numbers.

    Medium

    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 -> 3 represents the number 123.

    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 = [1,2,3]

    Output: 25

    Explanation: 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: root = [4,9,0,5,1]

    Output: 1026

    Explanation: 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.

    Constraints:

    • The number of nodes in the tree is in the range [1, 1000].
    • 0 <= Node.val <= 9
    • The depth of the tree will not exceed 10.

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • sumNumbers

        public int sumNumbers​(TreeNode root)