leetcode 199. Binary Tree Right Side View 求所能看到的叶子节点 ---------- java

Posted xiaoba1203

tags:

篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了leetcode 199. Binary Tree Right Side View 求所能看到的叶子节点 ---------- java相关的知识,希望对你有一定的参考价值。

Given a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see ordered from top to bottom.

For example:
Given the following binary tree,

   1            <---
 /   2     3         <---
 \       5     4       <---

 

You should return [1, 3, 4].

 

使用队列,层次遍历,每一层的最后一个节点。

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public List<Integer> rightSideView(TreeNode root) {
        
        List<Integer> list = new ArrayList();
        if (root == null){
            return list;
        }
        Queue<TreeNode> queue = new LinkedList();
        queue.add(root);
        while(!queue.isEmpty()){
            int size = queue.size();
            for (int i = 0; i < size; i++){
                TreeNode node = queue.poll();
                if (node.left != null){
                    queue.add(node.left);
                }
                if (node.right != null){
                    queue.add(node.right);
                }
                if (i == size - 1){
                    list.add(node.val);
                }
            }
        }
        return list;
    }
}

 


以上是关于leetcode 199. Binary Tree Right Side View 求所能看到的叶子节点 ---------- java的主要内容,如果未能解决你的问题,请参考以下文章

leetcode@ [199] Binary Tree Right Side View (DFS/BFS)

LeetCode 199. Binary Tree Right Side View

[leetcode] 199. Binary Tree Right Side View

[LeetCode] 199. Binary Tree Right Side View Java

LeetCode 199. 二叉树的右视图(Binary Tree Right Side View)

(二叉树 bfs) leetcode 199. Binary Tree Right Side View