题解 | #二叉树的深度#

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


func Print(root *TreeNode ) [][]int {
    ans := make([][]int, 0)
    if root == nil {
        return ans
    }
    queue := make([]*TreeNode, 0)
    queue = append(queue, root)
    for len(queue) > 0 {
        subNum := make([]int, 0)
        size := len(queue)
        for size > 0 {
            cur := queue[0]
            queue = queue[1:]
            if len(ans) % 2 == 0 {
                subNum = append(subNum, cur.Val)
            }else {
                //insert a value in a slice at a given index
                subNum = append(subNum, 0)
                copy(subNum[1:], subNum[0:]) 
                subNum[0] = cur.Val
            }
            if cur.Left != nil {
                queue = append(queue, cur.Left)
            }
            if cur.Right != nil {
                queue = append(queue, cur.Right)
            }
            size--
        }
        ans = append(ans, subNum)
    }
    return ans
}