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Array Left Rotation by D – C# Code

left rotation operation on an array of size n 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].

Given an array of  n integers and a number, d , perform d left rotations on the array. Then print the updated array as a single line of space-separated integers.

Input Format

The first line contains two space-separated integers denoting the respective values of  (the number of integers) and  (the number of left rotations you must perform).
The second line contains  space-separated integers describing the respective elements of the array’s initial state.

Output Format

Print a single line of  space-separated integers denoting the final state of the array after performing  left rotations.

Sample Input

5 4
1 2 3 4 5

Sample Output

5 1 2 3 4




 static int[] LeftRotationByD(int[] a,int k)
            int[] b = new int[a.Length];

            int index;
            int length = a.Length;
            int place;

            for (int i = 0; i < length; i++)
                index = i - k;
                place = length + index;
                if (index >= 0)
                    b[index] = a[i];
                    b[place] = a[i];
            return b;



We can see the results for 1 and 4 rotations as follows:




1 thought on “Array Left Rotation by D – C# Code

  1. Thank you for this solution. But this might fail if the number of rotations is grater than the array length.
    Sol: k= k % arr.Length==0?arr.Length:k % arr.Length;

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