标签：
原题链接：https://leetcode.com/problems/binary-tree-right-side-view/
题意描述：
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].
题解：
这道题非常有趣，是找二叉树从右侧看的时候能看到的数，其实思路也是很简单，即返回每一层的最右边的一个数就好了，在二叉树的层序遍历的代码上稍作修改即可。对二叉树的层序遍历不太清楚的朋友，可看我之前的博客《二叉树完全总结》。具体没什么好说的，直接上代码：
1 /** 2 * Definition for binary tree 3 * public class TreeNode { 4 * int val; 5 * TreeNode left; 6 * TreeNode right; 7 * TreeNode(int x) { val = x; } 8 * } 9 */ 10 public class Solution { 11 public List<Integer> rightSideView(TreeNode root) { 12 List<Integer> res = new ArrayList<Integer>(); 13 if(root==null) 14 return res; 15 Queue<TreeNode> Q = new LinkedList<TreeNode>(); 16 Q.offer(root); 17 int curLevel = 1; 18 res.add(root.val); 19 while(!Q.isEmpty()){ 20 int levelSize = Q.size(); 21 int count = 0; 22 TreeNode last = null; 23 while(count<levelSize){ 24 TreeNode p = Q.poll(); 25 if(p.left!=null){ 26 last = p.left; 27 Q.offer(p.left); 28 } 29 if(p.right!=null){ 30 last = p.right; 31 Q.offer(p.right); 32 } 33 count++; 34 } 35 if(last!=null) 36 res.add(last.val); 37 38 } 39 return res; 40 } 41 }
[LeetCode]Binary Tree Right Side View
标签：
原文地址：http://www.cnblogs.com/codershell/p/4396249.html
