199. Right view of binary tree - breadth search

class Solution {
    
public:
    vector<int> rightSideView(TreeNode* root) {
    
        vector<int> vecInt;
        if(!root)
            return vecInt;
        deque<TreeNode*> que;
        que.push_back(root);
        while(!que.empty()){
    
            int n = que.size();
            vecInt.push_back(que.back() -> val);    // Add the last element , That is, the rightmost element 
            for(auto i = 0; i < n; i++){
        // Level traversal 
                if(que.front() -> left)
                    que.push_back(que.front() -> left);
                if(que.front() -> right)
                    que.push_back(que.front() -> right);
                que.pop_front();
            }
        }
        return vecInt;
    }
};

Accepted
215/215 cases passed (4 ms)
Your runtime beats 65.19 % of cpp submissions
Your memory usage beats 90.76 % of cpp submissions (11.6 MB)