https://leetcode.com/problems/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].
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class node {
public:
TreeNode *nd;
int lv;
node(TreeNode *rhs, int l): nd(rhs), lv(l) {}
}; class Solution {
public:
vector<int> rightSideView(TreeNode* root) {
vector<pair<int, int> > load;
vector<int> res;
if(root == NULL) return res; stack<node> q;
q.push(node(root, ));
int lv = ; while(!q.empty()) {
node top = q.top();
int cur_lv = top.lv;
q.pop();
load.push_back(make_pair(top.nd->val, cur_lv)); if(top.nd->left) q.push(node(top.nd->left, cur_lv+));
if(top.nd->right) q.push(node(top.nd->right, cur_lv+));
} int elv = ;
for(int i=; i<load.size(); ++i) {
if(elv == load[i].second) {
res.push_back(load[i].first);
++elv;
}
} return res;
}
};