排序——堆排序

最新推荐文章于 2025-12-04 16:02:12 发布

原创最新推荐文章于 2025-12-04 16:02:12 发布 · 97 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#数据结构与算法

C/C++ 专栏收录该内容

7 篇文章

订阅专栏

本文深入解析堆排序算法的实现细节，包括最大堆的构建、最大堆的调整等关键步骤，详细解释了如何通过堆排序算法对数组进行排序。

static void max_heapify(int * arr, unsigned int beginPos, unsigned int length)
{
	unsigned int largest = 0;
	unsigned int left = 0;
	unsigned int right = 0;
	unsigned int tempPos = 0;
	int tempNum = 0;

	for(tempPos = beginPos, largest = tempPos; tempPos * 2 + 1 < length; tempPos = largest)
	{
		left = tempPos * 2 + 1;
		right = (tempPos + 1) * 2;
		/* 循环条件保证，l-child必定在范围内 */
		if(arr[tempPos] < arr[left])
		{
			largest = left;
		}
		if(right < length)
		{
			if(arr[largest] < arr[right])
			{
				largest = right;
			}
		}
		if(largest == tempPos)
		{
			break;
		}
		else
		{
			tempNum = arr[tempPos];
			arr[tempPos] = arr[largest];
			arr[largest] = tempNum;
		}
	}
	return;
}

static void build_max_heap(int * arr, unsigned int length)
{
	unsigned heapifyPos = 0;
	for(heapifyPos = (length - 2)/2;heapifyPos >= 0; --heapifyPos)
	{
		max_heapify(arr, heapifyPos, length);
		if(heapifyPos == 0)
		{
			break;
		}
	}
	return;
}


int heap_sort(int * arr, unsigned int length)
{
	unsigned int heapLast = 0;
	int tempNum = 0;
	if(arr == NULL)
	{
		return -1;
	}
	if(length < 2)
	{
		return 0;
	}
	build_max_heap(arr, length);
	for(heapLast = length - 1; heapLast > 0; --heapLast)
	{
		tempNum = arr[0];
		arr[0] = arr[heapLast];
		arr[heapLast] = tempNum;
		max_heapify(arr,0, heapLast);
	}
	return 0;
}