++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 给定一个二叉树,返回他的Z字形层次遍历的节点的values.(提示,从左到右,然后下一层从右到左,然后再变化方向,就是这样一层一层的遍历) 例如: 给定一个二叉树 {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 返回的层次遍历的结果是: [ [3], [20,9], [15,7] ] +++++++++…