fill

Question :

Write a function fill with signature

int[] fill(int[] arr, int k, int n)

which does the following: It returns an integer array arr2 of length n whose first k elements are the same as the first k elements of arr, and whose remaining elements consist of repeating blocks of the first k elements.  You can assume array arr has at least k elements. The function should return null if either k or n is not positive. 

Examples:  fill({1,2,3,5, 9, 12,-2,-1}, 3, 10) returns {1,2,3,1,2,3,1,2,3,1}. Fill({4, 2, -3, 12}, 1, 5)  returns {4, 4, 4, 4, 4}. fill({2, 6, 9, 0, -3}, 0, 4) returns null.

Solution :

public static int[] fill(int[] arr, int k, int n)

        {

            if (k < 1 || n < 1)

                return null;

            int[] arr2 = new int[n];

            int j = 0;

            for (int i = 0; i < n; i++)

            {

                if (j >= k)

                    j = 0;

                arr2[i] = arr[j];

                j++;

            }

            return arr2;

        }