堆排序(包括数列建堆及堆弹出)

#include<vector>
#include<iostream>
using namespace std;
void heapSort(int a[],int n)
{
	vector<int>cur;
	cur.push_back(0);
	for (int i = 0; i < n; i++)
	{
		cur.push_back(a[i]);
	}
	//数组大根堆化
	for (int root = n / 2; root >= 1; root--)
	{
		int rootele = cur[root];
		int child = 2 * root;
		while (child <= n)
		{
			if (child < n && cur[child] < cur[child + 1])child++;
			if (rootele > cur[child])break;
			cur[child / 2] = cur[child];
			child *= 2;
		}
		cur[child / 2] = rootele;
	}
	//从大根堆中提取
	for (int i = n-1; i >= 1; i--)
	{
		int x = cur[1];    //让x等于堆.top()
		int lstele = cur[i+1];    //让lstele等于被删除的堆尾
		cur.pop_back();    //删除堆尾
		int root = 1;
		int child = 2;
		while (child <= i)    //将lstele放入堆内合适位置
		{
			if (child < i && cur[child] < cur[child + 1])child++;
			if (lstele > cur[child])break;
			cur[root] = cur[child];
			root = child;
			child *= 2;
		}
		cur[root] = lstele;
		a[i] = x;
	}
}
int main()
{
	int test[10] = { 15,84,34,21,81,61,35,16,48,68 };
	heapSort(test, 10);
	for (int i = 0; i < 10; i++)
		cout << test[i] << ' ';
	return 0;
}
用一个vector数组cur模拟了堆,cur[0]随便压了个0,一直没用到,写的简陋。

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转载自blog.csdn.net/weixin_40736096/article/details/79601053