Binary Tree Right Side View

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]

.

#include<iostream>
#include<vector>
#include<queue>
using namespace std;

struct TreeNode {
int val;
TreeNode *left;
TreeNode *right;
TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};
vector<int> rightSideView(TreeNode *root) {
vector<int>Result;
if (root == NULL)
return Result;
queue<pair<TreeNode*, int>>Queuenode;
TreeNode* TmpHead = root;
Queuenode.push(make_pair(TmpHead, 0));
pair<TreeNode*, int>deletenode(NULL, 0);
while (!Queuenode.empty())
{
TmpHead = Queuenode.front().first;
int curlevel = Queuenode.front().second;
if (deletenode.second != curlevel)
Result.push_back(deletenode.first->val);
if (TmpHead->left)
Queuenode.push(make_pair(TmpHead->left, curlevel + 1));
if (TmpHead->right)
Queuenode.push(make_pair(TmpHead->right, curlevel + 1));
deletenode = Queuenode.front();
Queuenode.pop();
}
Result.push_back(deletenode.first->val);
return Result;
}