C#_基础：排序算法

        //希尔排序
        static int[] ShellSort(int[] array)
        {
            if (array != null)
            {
                int[] list = { 9, 5, 3, 2, 1 };
                foreach (int k in list)
                {
                    for (int i = k; i < array.Length; i++)
                    {
                        int current = array[i];
                        int preIndex = i - k;
                        while (preIndex >= 0 && preIndex < array.Length && current < array[preIndex])
                        {
                            array[preIndex + k] = array[preIndex];

                            preIndex = preIndex - k;
                        }
                        array[preIndex + k] = current;
                    }
                }
            }
            return array;
        }
        //插入排序
        public int[] InsertSort(int[] array)
        {
            if (array != null)
            {
                int k = 1;//使用k变量，后面更好的扩展到Shell排序
                for (int i = k; i < array.Length; i++)
                {
                    int current = array[i];
                    int preIndex = i - k;
                    while (preIndex >= 0 && preIndex < array.Length && current < array[preIndex])
                    {
                        array[preIndex + k] = array[preIndex];

                        preIndex = preIndex - k;
                    }
                    array[preIndex + k] = current;
                }
            }
            return array;
        }
        //冒泡排序
        public int[] BubbleSort(int[] array)
        {
            if (array != null)
            {
                for (int i = 0; i < array.Length; i++)
                {
                    for (int j = 1; j < array.Length - i; j++)
                    {
                        if (array[j - 1] > array[j])
                            {
                                int temp = array[j - 1];
                                array[j - 1] = array[j];
                                array[j] = temp;
                            }
                    }
                }
            }
            return array;
        }