Binary Tree Right Side View

Smrita Pokharel

·Apr 12, 2021

public List<Integer> rightSideView(TreeNode root) {
        
        return rightSideViewBFS(root);
    }
    
    private List<Integer> rightSideViewBFS(TreeNode root){
        
        List<Integer> result = new ArrayList<Integer>();
        
        if(root==null){
            return result;
        }
       
        Queue<TreeNode> queue = new LinkedList<TreeNode>();
        
        queue.add(root);
        
        while(queue.size() != 0){
            int size = queue.size();
            
            for (int i=0; i<size; i++) {
                
                TreeNode node = queue.remove();
                    
                if(i==0){
                    result.add(node.val);
                }
                
                if(node.right!=null){
                    queue.add(node.right);
                }
                
                if(node.left!=null){
                    queue.add(node.left);
                }
                
            }
        }
            
        return result;
        
    }