剑指OFFER----34、二叉树中和为某一值的路径(js实现)

题目

• 输入一颗二叉树和一个整数，打印出二叉树中结点值的和为输入整数的所有路径。从树的根结点开始往下一直到叶结点所经过的结点形成一条路径。
• leetcode链接：https://leetcode-cn.com/problems/er-cha-shu-zhong-he-wei-mou-yi-zhi-de-lu-jing-lcof/

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思路

• 前序遍历

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代码

/**
 * 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
 * @param {number} target
 * @return {number[][]}
 */
var pathSum = function (root, target) {
  const result = []
  function order(node, sum, path) {
    if (!node) return
    const currentSum = node.val + sum
    const currentPath = [...path, node.val]
    if (currentSum === target && !node.left && !node.right) {
      result.push([...currentPath])
      return
    }
    order(node.left, currentSum, currentPath)
    order(node.right, currentSum, currentPath)
  }
  order(root, 0, [])
  return result
}