public static void mergeSort(int[] array, int p, int r)
    {
        if(p<r)
        {

            int q = (p+r)/2;
            mergeSort(array,p,q);
            mergeSort(array,q+1,r);
            merge(array,p,q,r);
        }
    }

    public static void merge(int[] array, int p, int q, int r)
    {
        int[] hilfsarray = new int[array.length];
        int i,j;
        for(i = 1; i<= q; i++)
        {
            hilfsarray[i] = array[i];
        }

        for(j = q+1; j <= r; j++)
        {
            hilfsarray[r+q+1-j] = array[j];
        }

        i = p;
        j = r;

        for(int k = 1; k<= r; k++)
        {
            if(hilfsarray[i] <= hilfsarray[j])
            {
                array[k] = hilfsarray[i];
                i++;
            }
            else
            {
                array[k] = hilfsarray[j];
                j++;
            }
        }
    }