插入排序算法之希尔排序+直接插入排序

end--；
x = a[end + 1];

for(i = 0; i < n - 1; i++)
{
    
}

//插入排序
void InsetSort(int* a, int n)
{
	int end = 0;
	int i = 0;

	for (i = 0; i < n - 1; i++)
	{
		end = i;
		int x = a[end + 1];

		while (end >= 0)
		{
			if (a[end] > x)
			{
				a[end + 1] = a[end];
				a[end] = x;
				
			}
			else
			{
				break;
			}
			end--;
		}
	}
	
}

int main()
{
	int a[4] = { 2, 6, 5, 3 };
	InsetSort(a, 4);
	//ShellSort(a, 4);

	int i = 0;
	for (i = 0; i < 4; i++)
	{
		printf("%d ", a[i]);

	}
	printf("\n");

	return 0;
}

//希尔排序
void ShellSort(int* a, int n)
{
	int end = 0;
	int i = 0;
	int j = 0;
	int gap = 6;

	//预排序
	for (j = 0; j < gap; j++)
	{
		//最后一个数一定是1
		gap = gap / 2;
		for (i = 0; i < n - gap; i++)
		{
			end = i;
            //这里其实就是直接插入排序，而数组的每个元素间隔是gap
			int x = a[end + gap];

			while (end >= 0)
			{
				if (a[end] > x)
				{
					a[end + gap] = a[end];
					a[end] = x;

				}
				else
				{
					break;
				}
				end -= gap;
			}
		}

	}
}

//性能测试
void TestOP()
{
	srand(time(0));
    //以1000个数字为例
	const int N = 10000;
	int* a1 = (int*)malloc(sizeof(int) * N);
	int* a2 = (int*)malloc(sizeof(int) * N);

	for (int i = 0; i < N; ++i)
	{
		a1[i] = rand();
		a2[i] = a1[i];
	}
    //这里clock是运行到这里的时间
	int begin1 = clock();
	InsertSort(a1, N);
	int end1 = clock();

	int begin2 = clock();
	ShellSort(a2, N);
	int end2 = clock();
    //end-begin为排序所用时间
	printf("%d\n%d\n", end1 - begin1, end2 - begin2);
}