1305. 两棵二叉搜索树中的所有元素🔖DFS🔖数组

• https://leetcode-cn.com/problems/all-elements-in-two-binary-search-trees/

/**

- 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} root1
- @param {TreeNode} root2
- @return {number[]}
  \*/
  var getAllElements = function(root1, root2) {
  let arr_left = []
  let arr_right = []
  let dfs = (data, arr) => {
  if (data) {
  dfs(data.left, arr)
  dfs(data.right, arr)
  arr.push(data.val)
  }
  }
  dfs(root1, arr_left)
  dfs(root2, arr_right)
  return arr_left.concat(arr_right).sort((a, b) => {return a - b})
  };