Sum Root to Leaf Numbers

Description

ref

Solution

Recursive Solution

/**
 * Definition for a binary tree node.
 * function TreeNode(val, left, right) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.left = (left===undefined ? null : left)
 *     this.right = (right===undefined ? null : right)
 * }
 */
/**
 * @param {TreeNode} root
 * @return {number}
 */
var sumNumbers = function (root) {
  function sum(node) {
    if (!node) {
      return []
    }

    if (!node.left && !node.right) {
      return [`${node.val}`]
    }

    return [...sum(node.left), ...sum(node.right)].map((v) => node.val + v)
  }

  return sum(root).reduce((acc, cur) => acc + Number.parseInt(cur), 0)
}