Associate Software Engineer

You are given an array 'ARR' of integers of length N. Your task is to find the first missing positive integer in linear time and constant space. In other words, find the lowest positive integer that does not exist in the array. The array can have negative numbers as well.

For example, the input [3, 4, -1, 1] should give output 2 because it is the smallest positive number that is missing in the input array.

You have been given a Binary Tree of 'N'

nodes, where the nodes have integer values.

Your task is to return the ln-Order, Pre-Order, and Post-Order traversals of the given binary tree.

For example :

For the given binary tree:

The Inorder traversal will be [5, 3, 2, 1, 7, 4, 6].
The Preorder traversal will be [1, 3, 5, 2, 4, 7, 6].
The Postorder traversal will be [5, 2, 3, 7, 6, 4, 1].

You are given an array 'ARR' of integers of length 'N' and a positive integer 'K'. You need to find the maximum elements for each and every contiguous subarray of size K of the array.

For example

'ARR' =  [3, 4, -1, 1, 5] and 'K' = 3
Output =  [4, 4, 5]

Since the maximum element of the first subarray of length three ([3, 4, -1]) is 4, the maximum element of the second subarray of length three ([4, -1, 1]) is also 4 and the maximum element of the last subarray of length three ([-1, 1, 5]) is 5, so you need to return [4, 4, 5].