题解 | #按之字形顺序打印二叉树#

package main
import . "nc_tools"
/*
 * type TreeNode struct {
 *   Val int
 *   Left *TreeNode
 *   Right *TreeNode
 * }
 */

/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 * 
 * @param pRoot TreeNode类 
 * @return int整型二维数组
*/
func Print( pRoot *TreeNode ) [][]int {
    // write code here
    root := pRoot
	res := make([][]int, 0)
	if root == nil {
		return nil
	}
	level := make([]*TreeNode, 0)
	level = append(level, root)
	floor := 1
	for len(level) != 0 {
		size := len(level)
		tmpNode := make([]*TreeNode, 0)
		tmp := make([]int, 0)
		for i := 0; i < size; i++ {
			curr := level[0]
			level = level[1:]
			if floor%2 == 0 {
				tmp = append([]int{curr.Val}, tmp...)
			} else {
				tmp = append(tmp, curr.Val)
			}
			if curr.Left != nil {
				tmpNode = append(tmpNode, curr.Left)
			}
			if curr.Right != nil {
				tmpNode = append(tmpNode, curr.Right)
			}
		}
		floor++
		level = tmpNode
		res = append(res, tmp)
	}
	return res
}