leetcode 199 二叉树的右视图 c++

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    vector<int> rightSideView(TreeNode* root) {
        vector<int>view;
        queue<pair<TreeNode*,int>>Q;
        if(root){
            Q.push(make_pair(root,0));
        }
        while(!Q.empty()){
            TreeNode *node=Q.front().first;
            int depth=Q.front().second;
            Q.pop();
            if(view.size()==depth){
                view.push_back(node->val);
            }
            else{
                view[depth]=node->val;
            }
            if(node->left){
                Q.push(make_pair(node->left,depth+1));
            }
            if(node->right){
                Q.push(make_pair(node->right,depth+1));
            }
        }
        return view;
    }
};