[数据结构与算法]Go语言层次遍历二叉树

?层次遍历二叉树leetcode

剑指 Offer 32 - I. 从上到下打印二叉树 https://leetcode-cn.com/problems/cong-shang-dao-xia-da-yin-er-cha-shu-lcof/

剑指 Offer 32 - II. 从上到下打印二叉树https://leetcode-cn.com/problems/cong-shang-dao-xia-da-yin-er-cha-shu-ii-lcof/

剑指 Offer 32 - III. 从上到下打印二叉树https://leetcode-cn.com/problems/cong-shang-dao-xia-da-yin-er-cha-shu-iii-lcof/?

type TreeNode struct {
      Val int
      Left *TreeNode
      Right *TreeNode
 }
func levelOrder(root *TreeNode) []int {
    res := make([]int, 0)
    if root == nil {
        return res
    }

    queue := make([]*TreeNode, 0)
    queue = append(queue, root)
    for len(queue) != 0{
        l := len(queue)
        for l > 0{
            l --
            node := queue[0]
            queue = queue[1:]
            res = append(res, node.Val)
            if node.Left != nil{
                queue = append(queue, node.Left)
            }
            if node.Right != nil{
                queue = append(queue, node.Right)
            }
        }
    }
    return res
}