希尔排序

        int[] arr = {1, 52, 12, 36, 45,6,4,32,12,15,34,76};

        // 希尔排序
        shellSort(arr);

// 希尔排序
private static void shellSort(int[] arr) {
   if(arr==null||arr.length<=1){
       return;
   }
    int len = arr.length;
    int tem ;
    int gap = len/2;  //增量，或者一个分组的数量
    while (gap>0){
        for (int i = gap; i < len; i++) {
           int preIndex = i-gap;
           tem = arr[i];
           // 加一个插入排序
           while (preIndex>=0&& arr[preIndex]>tem){
               arr[preIndex+gap] = arr[preIndex];
               preIndex = preIndex-gap;
           }
         arr[preIndex+gap] = tem;
        }
        gap=gap/2;
   }
    System.out.println(Arrays.toString(arr));
}