Hackerank: Interview Prep Kit: Array: Left Rotation.

Hello friends, we are going to be solving a problem I found on Hackerank, please stay focused as I share the problem and provide an answer. I will be providing answers majorly in Javascript and Dart.

Problem

A left rotation operation on an array shifts each of the array's elements 1 unit to the left. For example, if 2 left rotations are performed on array [1,2,3,4,5], then the array would become [3,4,5,1,2. Note that the lowest index item moves to the highest index in a rotation. This is called a circular array.
Given an array a of n integers and a number, d, perform d left rotations on the array. Return the updated array to be printed as a single line of space-separated integers.

Function Description

Complete the function rotLeft in the editor below.
rotLeft has the following parameter(s):
* int a[n]: the array to rotate
* int d: the number of rotations

Return

* int a'[n]: the rotated array

Input Format

The first line contains two space-separated integers n and d, the size of a and the number of left rotations.
The second line contains n space-separated integers, each an a[i].

Sample Input

5 4
1 2 3 4 5

Sample Output

5 1 2 3 4

Explanation

When we perform d = 4 left rotations, the array undergoes the following sequence of changes:
[1,2,3,4,5] -> [2,3,4,51] -> [3,4,5,1,2] -> [4,5,1,2,3] -> [5,1,2,3,4]

Solution in JS

Solution in Dart

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