package io.github.dreamylost /** * 镜像二叉树非递归 * * @author liguobin@growingio.com * @version 1.0,2020/3/18 */ object Interview_27 extends App { //层次遍历-QUEUE def mirrorTree(root: TreeNode): TreeNode = { import scala.collection.mutable val queue = mutable.Queue[TreeNode]() queue.enqueue(root) while (queue.nonEmpty) { val tmp = queue.dequeue() if (tmp != null) { val left = tmp.left tmp.left = tmp.right tmp.right = left queue.enqueue(tmp.right) queue.enqueue(tmp.left) } } root } }