堆排序C++实现

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//堆排序C++实现
#include<iostream>
#include<functional>

using namespace std;

void HeapSort(int* arr, int cnt)
{
	function<void(int*, int, int)> percdown = [&](int* arr, int i, int cnt)  //下滤操作
	{
		int child = 0, tmp = 0;
		for (tmp = arr[i]; 2 * i + 1 < cnt; i = child)
		{
			child = i * 2 + 1;
			if (child != cnt - 1 && arr[child + 1] > arr[child])
				child++;
			if (tmp < arr[child])
				arr[i] = arr[child];
			else
				break;
		}
		arr[i] = tmp;
	};

	for (int i = (cnt-1) / 2; i >= 0; i--)   //从最后一个元素的父节点开始一个一个的下滤，构建堆 注意：这里的i = cnt 或 cnt -1 均可，可以自行画图解释
		percdown(arr, i, cnt);
	for (int i = cnt - 1; i > 0; i--)   //把构建好的堆进行排序
	{
		swap(arr[0], arr[i]);
		percdown(arr, 0, i);
	}
}

int main()
{
	const int cnt = 1159;
	int arr[cnt];
	int tmp = -1;
	for (int i = 0; i < cnt; i++)
	{
		if (i % 2)
			arr[i] = i;
		else
			arr[i] = i * tmp;
	}
	HeapSort(arr, cnt);
	for (auto i : arr)
		cout << i << endl;
	for (int i = 0; i < cnt-1; i++)
	{
		if (arr[i]  > arr[i + 1])
			cout << "haha" << endl;
	}
	cout << "test end" << endl;


	cin.get();
	return 0;
}

堆排序C++实现

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原文地址：http://blog.csdn.net/linukey/article/details/46476755