java数据结构和算法------合并排序

package iYou.neugle.sort;

public class Merge_sort {

    public static void MergeSort(double[] array, int start, int end) {
        if (start < end) {
            int middle = (start + end) / 2;
            MergeSort(array, start, middle);
            MergeSort(array, middle + 1, end);
            Merge(array, start, middle, end);
        }
    }

    private static void Merge(double[] array, int start, int middle, int end) {
        int n1 = middle - start + 1;
        int n2 = end - middle;
        double[] L = new double[n1];
        double[] R = new double[n2];
        for (int i = 0; i < n1; i++) {
            L[i] = array[start + i];
        }
        for (int i = 0; i < n2; i++) {
            R[i] = array[middle + i + 1];
        }
        for (int i = 0, j = 0, k = start; k <= end; k++) {
            if (j == n2 || (i < n1 && L[i] <= R[j])) {
                array[k] = L[i];
                i++;
            } else {
                array[k] = R[j];
                j++;
            }
        }
    }
}