Q1: List of numbers with unique values as I put. And need to have a result like this [1,4,5,2,3,9,8,11,0] => "0-5,8-9,11"' [1,4,3,2] => "1-4" Q2: Given a tree with character values only, 2 nodes are similar if the set of elements in that subtrees have same elements. Find whether there are any similar nodes.