归并排序

public class TestMergeSort{    public static void merge(int[] a, int low, int mid, int high)    {        int[] temp = new int[high - low + 1];        int i = low;//left pointer        int j = mid + 1;//right pointer        int k = 0;        //move smaller element to new array        while (i <= mid && j <= high)        {            if (a[i] < a[j])            {                temp[k++] = a[i++];            }            else            {                temp[k++] = a[j++];            }        }        // left on left side        while (i <= mid)        {            temp[k++] = a[i++];        }        //left on right        while (j <= high)        {            temp[k++] = a[j++];        }        //copy to old array         for (int k2 = 0; k2 < temp.length; k2++)        {            a[k2 + low] = temp[k2];        }    }    static void mergeSort(int[] r, int low, int high)    {        if (low < high)        {            int mid = (low + high) / 2;            mergeSort(r, low, mid);            mergeSort(r, mid + 1, high);            merge(r, low, mid, high);        }    }    public static void display(int[] R)    {        System.out.println();        for (int i = 0; i < R.length; i++)        {            System.out.print(R[i] + " ");        }    }    public static void main(String[] args)    {        int[] R = { 71, 88, 93, 77, 5, 16, 63, 74, 89, 18 };        display(R);        mergeSort(R, 0, R.length - 1);        display(R);    }}