排序六：希尔排序

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ShellSort
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] arr = new int[10];
            Random rd = new Random();
            for (int i = 0; i < arr.Length; i++)
            {
                //arr[i] = rd.Next(10);
                arr[i] = arr.Length - i;
            }
            ShellSort(arr);
            foreach (int i in arr)
                Console.WriteLine(i);
        }

        public static void ShellSort(int[] arr)
        {
            int temp, k;
            int len = arr.Length / 2;
            for (int gap = len; gap > 0; gap /= 2)
            {
                for (int j = gap; j < arr.Length; j++)
                {
                    temp = arr[j];
                    k = j - gap;
                    while (k >= 0 && arr[k] > temp)
                    {
                        arr[k + gap] = arr[k];
                        k -= gap;
                    }
                    arr[k+gap] = temp;
                }
            }
        }

        public static void Swap(int[] arr, int a, int b)
        {
            int temp = arr[a];
            arr[a] = arr[b];
            arr[b] = temp;
        }
    }
}