Merge Sort

public void sort()
{
   if (a.length <= 1) return;
   int[] first = new int[a.length / 2];
   int[] second = new int[a.length - first.length];
   System.arraycopy(a, 0, first, 0, first.length);
   System.arraycopy(a, first.length, second, 0, second.length);
   MergeSorter firstSorter = new MergeSorter(first);
   MergeSorter secondSorter = new MergeSorter(second);
   firstSorter.sort();
   secondSorter.sort();
   merge(first, second);
}