LeetCode:Binary Tree Right Side View

题目描述：

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].

思路分析：层序遍历二叉树，将每层最后一个节点的值保存到结果中。

代码：

class Solution{public:vector<int> rightSideView(TreeNode * root){queue<TreeNode *> temp_queue;vector<int> result;if(root == NULL)return result;temp_queue.push(root);while(!temp_queue.empty()){int val = temp_queue.back()->val;result.push_back(val);int queue_size = temp_queue.size();for(int i = 0;i < queue_size;i++){TreeNode * temp_treeNode = temp_queue.front();temp_queue.pop();if(temp_treeNode->left != NULL)temp_queue.push(temp_treeNode->left);if(temp_treeNode->right != NULL)temp_queue.push(temp_treeNode->right);}}return result;}};