Backend Developer

You are given a singly linked list ‘HEAD’ consisting of ‘N’ nodes. The task is to group all the odd nodes together, followed by the even nodes, maintaining the relative order of nodes given in the input. Note that we are talking about the node’s positions and not the value stored in the node. Try to write an in-place algorithm (i.e., without using any extra space) to solve this problem.

Example:

Given linked list: ‘2 => 1 => 3 => 4 => 6 => 5’

While maintaining the relative order of nodes as it is in the input, Nodes at odd positions are (2, 3, 6), and nodes at evens position are (1, 4, 5).

Modified linked list: ‘2 => 3 => 6 => 1 => 4 => 5’

Note:

1. Consider that the first node is odd, the second is even, and so on.

Given an array/list of integers of length ‘N’, there is a sliding window of size ‘K’ which moves from the beginning of the array, to the very end. You can only see the ‘K’ numbers in a particular window at a time. For each of the 'N'-'K'+1 different windows thus formed, you are supposed to return the maximum element in each of them, from the given array/list.

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.