Software Engineer

You are given a linked list containing 'n' nodes, where every node in the linked list contains two pointers:

(1) ‘next’ which points to the next node in the list

(2) ‘random’ which points to a random node in the list or 'null'.

Your task is to create a 'deep copy' of the given linked list and return its head.

Note:

A 'deep copy' of a linked list means we do not copy the references of the nodes of the original linked list, rather for each node in the original linked list, a new node is created.

You have a binary tree of 'N' unique nodes and a Start node from where the tree will start to burn. Given that the Start node will always exist in the tree, your task is to print the time (in minutes) that it will take to burn the whole tree.

It is given that it takes 1 minute for the fire to travel from the burning node to its adjacent node and burn down the adjacent node.

For Example :

For the given binary tree: [1, 2, 3, -1, -1, 4, 5, -1, -1, -1, -1]
Start Node: 3

    1
   / \
  2   3
     / \
    4   5

Output: 2

Explanation :
In the zeroth minute, Node 3 will start to burn.

After one minute, Nodes (1, 4, 5) that are adjacent to 3 will burn completely.

After two minutes, the only remaining Node 2 will be burnt and there will be no nodes remaining in the binary tree. 

So, the whole tree will burn in 2 minutes.

Design a Rewards System.
requirement:
1. User should be able to see available rewards.
2. User should be able to claim rewards.
3. Rewards may have a eligibility criteria like referrals, min transactions
4. The system should be highly scalable and robust.
5. There should be no Single Point of Failure