Binary Tree Right Side View

 Binary Tree Right Side View

Given the root of 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.

 

Example 1:

Input: root = [1,2,3,null,5,null,4]
Output: [1,3,4]

Example 2:

Input: root = [1,null,3]
Output: [1,3]

Example 3:

Input: root = []
Output: []

 

Constraints:

• The number of nodes in the tree is in the range [0, 100].
• -100 <= Node.val <= 100

Solution to to the above question

class Solution {

public:vector<int>v;

    vector<int>ans;

        

    vector<int> rightSideView(TreeNode* root) {

        if(root==NULL){

            return ans;

        }

       

        queue<TreeNode*>q;

        q.push(root);

        q.push(NULL);

  

        while(!q.empty()){

            TreeNode* temp=q.front();

            q.pop();

            if(temp==NULL){

                v.push_back(ans[0]);

                ans.clear();

                if(!q.empty()){

                    q.push(NULL);

                }

            }

            else{

                ans.push_back(temp->val);

                if(temp->left!=NULL){

                q.push(temp->left);

            }

            if(temp->right!=NULL){

                q.push(temp->right);

            } 

            }

            

            ans.clear();

        }

        

        return v;

    }

};