题解 | #从上往下打印二叉树#
从上往下打印二叉树
http://www.nowcoder.com/practice/7fe2212963db4790b57431d9ed259701
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 root TreeNode类
- @return int整型一维数组 */ func PrintFromTopToBottom( root *TreeNode ) []int { // write code here queue := make([]*TreeNode, 0) res := make([]int, 0) if root == nil { return res } //根节点入队 queue = append(queue, root) for len(queue) != 0 { //队列首元素出队, 左右子节点入队 res = append(res, queue[0].Val) if queue[0].Left != nil { queue = append(queue, queue[0].Left) } if queue[0].Right != nil { queue = append(queue, queue[0].Right) } queue = queue[1:] } return res }
