private static final int SHUFFLE_COUNT = 5;


private static int[] VALUES = {1, 2, 3, 4, 5, 6};


//broken for when  SHUFFLECOUNT and VALUES are EVEN
public static void perfectShuffle(int[] values) {
    int[] values1 = Arrays.copyOf(values, values.length);
    int k = 0;
    for(int j = 0; j <= values.length / 2; j++) {
        values[k] = values1[j];
        k = k + 2;
    }
    k = 1;
    for(int j = (values.length / 2) + 1; j < values.length; j++) {
        values[k] = values1[j];
        k = k + 2;
    }

}

public void testPerfectShuffle() {
    System.out.println("Results of " + SHUFFLE_COUNT +
                             " consecutive perfect shuffles:");
    for (int j = 1; j <= SHUFFLE_COUNT; j++) {
        perfectShuffle(VALUES);
        System.out.println("  " + j + ":" + Arrays.toString(VALUES));
    }
    System.out.println();
}