堆排序

#include<iostream>
#include<algorithm>
using namespace std;

void HeapAdjust(int *a, int i, int size)
{
	int lchild = 2 * i;
	int rchild = 2 * i + 1;
	int max = i;
	if (i <= size / 2)
	{
		if (lchild <= size && a[lchild] > a[max])
			max = lchild;
		if (rchild <= size&& a[rchild] > a[max])
			max = rchild;
		if (max != i)
		{
			swap(a[i], a[max]);
			HeapAdjust(a, max, size);
		}
	}
}

void BuildHeap(int *a, int size)
{
	int i;
	for (i = size / 2; i >= 1; i--)
		HeapAdjust(a, i, size);
}

void HeapSort(int *a, int size)
{
	int i;
	BuildHeap(a, size);
	for (i = size; i >= 1; i--)
	{
		swap(a[1], a[i]);
		HeapAdjust(a, 1, i - 1);
	}
}

int main()
{
	int size, a[100], i;
	cout << "size" << endl;
	cin >> size;
	for (i = 1; i <= size; i++)
		cin >> a[i];
	HeapSort(a, size);
	for (i = 1; i <= size; i++)
		cout << a[i] << "  ";
	return 0;
}