Rotate an array by K position using Popup and Unshifting Algorithm in C#

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Rotate an array by K position using Popup and Unshifting Algorithm in C#

In this article, I am going to discuss Rotate an array by K position using Popup and Unshifting Algorithm in C# with Examples. Please read our previous article where we discussed Right Rotation of Array by 1 in C#. Rotation of an array basically means shifting each and every element to specified positions to the left or right. While writing the program for array rotation we should consider 2 factors:

1. The direction of Rotation – In what direction do we want to perform the rotation. Whether it would be left to right (clockwise) or right to left (anticlockwise).
2. Position of Rotation – At which position rotation will start.

Note: Rotation of array by position k (1,2,3 etc. depends on user input) means we need to shift the elements to the left or right side by k position.

Example: Rotate this array by position 2

So, by position 2 means each element will be shifted to the left side 2 times like 1 has shifted from index 2 to index 0 (2-0 = 2) as shown in the below fig.

Popup and Unshifting Algorithm is same as Rotation of array by 1 which we have discussed earlier. Let’s understand this with an example, suppose we want “3” as the output on our screen we can get this by adding 1 to 3 times i.e., (1+1+1=3). Same way, if we want to rotate an array by the position of 3 we can do this by doing a rotation of the array by 1 to 3 times.

Which is,
1st Time: Rotation of array by 1,
2nd Time: Rotation of array by 1,
3rd Time: Rotation of array by 1
And we will get our Rotation of array by 3.

Demonstration:

So, as you can see from the above fig. We have successfully completed the rotation of the array of position 3. The element 4 at index 3 has been shifted to index 0 (3-0). Likewise, all the elements have been shifted to position 3.

Algorithm to rotate an array by 1 (Left Rotation)

Step1: Create a Temp variable to store the value at index 0.
Step2: Sift all the elements of array to left side by position 1 i.e. arr[i] = arr[i+1];
Step3: Store the value of temp at the last index of array i.e. arr[(arr.Length – 1)] = x;

Algorithm to rotate an array by k

Step1: Take the value of position from the user and initialize a variable k with 0.
Step3: Call the function of left rotation of array by 1.
Step4: Increment the value of k i.e. k++;
Step5: Repeat steps 3 & 4 till the k value is less than the position value.
Step6: Display the rotated array.

Example:

The following C# Program performs rotation of array by position k using popup and unshifting algorithm.

using System;
namespace DotNetTutorials
{
    public class RotationOfArray
    {
        static void Main(string[] args)
        {
            int[] arr = new int[] { 1, 2, 3, 4, 5 };
            int position = 0, k = 0;
            Console.Write("Original Array :");
            for (int i = 0; i < arr.Length; i++)
            {
                Console.Write(arr[i] + " ");
            }
            Console.WriteLine();

            Console.Write("Enter position of rotation : ");
            position = Convert.ToInt32(Console.ReadLine());

            RotationOfArray obj = new RotationOfArray();
            while (k < position)
            {
                obj.LeftRotate(arr);
                k++;
            }

            Console.WriteLine("Rotation of array by position " + position);
            for (int i = 0; i < arr.Length; i++)
            {
                Console.Write(arr[i] + " ");
            }

            Console.ReadKey();
        }

        void LeftRotate(int[] arr)
        {
            int x = arr[0];
            for (int i = 0; i < (arr.Length - 1); i++)
            {
                arr[i] = arr[i + 1];
            }
            arr[(arr.Length - 1)] = x;
        }
    }
}

Output:

In the next article, I am going to discuss Rotate an array by K position using reversal algorithm in C# with Examples. Here, in this article, I try to explain Rotate an array by K position using Popup and Unshifting Algorithm in C# with Examples and I hope you enjoy this Rotate an array by position k by using Popup and Unshifting Algorithm in C# article.