数据结构与算法-希尔排序

代码实现：

//希尔排序
        public static void ShellSort(int[] arr)
        {

            for (int gap= arr.Length/2;  gap>0; gap=gap/2)
            {
                for (int i = gap; i<arr.Length ; i++)
                {
                    for (int j = i; j - gap >= 0; j -= gap)
                    {
                        if (arr[j] < arr[j - gap])
                        {
                            ExchangeLocation(arr, j, j - gap);
                        }
                    }
                }
            }
        }

 

根据优化后的间隔序列的代码实现

 //优化后希尔排序
        public static void OptimizedShellSort(int[] arr)
        {
            
            int h = 1;

            while (h < arr.Length / 3)
            {
                h= 3*h + 1;
            }


            for (int gap = h; gap > 0; gap = (gap-1)/3)
            {
                for (int i = gap; i < arr.Length; i++)
                {
                    for (int j = i; j - gap >= 0; j -= gap)
                    {
                        if (arr[j] < arr[j - gap])
                        {
                            ExchangeLocation(arr, j, j - gap);
                        }
                    }
                }
            }
        }

 //优化后希尔排序2
        public static void OptimizedShellSort2(int[] arr)
        {

            int h = 1;

            while (h < arr.Length / 3)
            {
                h = 3 * h + 1;
            }


            for (int gap = h; gap > 0; gap = (gap - 1) / 3)
            {
                for (int i = gap; i < arr.Length; i++)
                {
                    for (int j = i; j - gap >= 0; j -= gap)
                    {
                        int oriValue = arr[j];
                        int curr_index = j;

                        if (oriValue < arr[j - gap])
                        {
                            arr[j] = arr[j - gap];
                            curr_index = j - gap;
                            //ExchangeLocation(arr, j, j - gap);
                        }

                        arr[curr_index] = oriValue;
                    }
                }
            }
        }