java实现的排序(插入/希尔/归并)

java实现三种简单的排序,以下是代码:

 /*插入排序*/
 public static void insertionSort(int[] a)
 {
     int j;
     for(int p = 1; p < a.length; p++)
     {
         int tmp = a[p];
         for(j = p; j > 0 && tmp < a[j - 1]; j--)
             a[j] = a[j - 1];
         a[j] = tmp;
     }

 }
 //-----------------------------------------------------------  keleyi.com
 /*希尔排序*/
 public static void shellsort(int[] a)
 {
     int j;

     for(int gap = a.length / 2; gap > 0; gap /= 2)
         for(int i = gap; i < a.length; i++)
         {
             int tmp = a[i];
             for(j = i; j >= gap && tmp < a[j - gap]; j-=gap)
                 a[j] = a[j - gap];
             a[j] = tmp;
         }
 }
 //-----------------------------------------------------------
 /*归并排序*/
 private static void mergeSort(int []a, int []tmpArray, int left, int right)
 {
     if(left < right)
     {
         int center = (left + right) / 2;
         mergeSort(a, tmpArray, left, center);
         mergeSort(a, tmpArray, center + 1, right);
         merge(a, tmpArray, left, center + 1, right);
     }
 }
 public static void mergeSort(int []a)
 {
     mergeSort(a, tmpArray, 0, a.length - 1);
 }