Diagonal Traversal

Input : root = [8, 3, 10, 1, 6, N, 14, N, N, 4, 7, 13]
            8
         /     \
        3      10
      /   \      \
     1     6     14
         /   \   /
        4     7 13
Output : [8, 10, 14, 3, 6, 7, 13, 1, 4]
Explanation:
unnamed
Diagonal Traversal of binary tree : 8 10 14 3 6 7 13 1 4


class Tree
{
     public ArrayList<Integer> diagonal(Node root)
      {
           //add your code here.
           ArrayList<Integer> result = new ArrayList<>();
           if(root==null){
               return result;
           }
           
           Queue<Node> q = new LinkedList<>();
           q.add(root);
           
           while(!q.isEmpty()){
               Node curr = q.remove();
               
               while(curr!=null){
                   result.add(curr.data);
                   
                   if(curr.left!=null){
                       q.add(curr.left);
                   }
                   curr = curr.right;
               }
           }
           return result;
      }
}