堆排序

#include<iostream>
#include<vector>
#include <bitset>
#include<algorithm>
#include<map>
#include<unordered_map>
#include<string>
#include<unordered_set>
#include<set>
using namespace std;

void Heapfy(int a[], int idx, int max)//堆调整
{
    int left = idx * 2 + 1;
    int right = left + 1;
    int largest = idx;
    if (left<max&&a[left]>a[largest])// 大于号是升序，小于号是降序
    {
        largest = left;
    }
    if (right < max&&a[right]>a[largest])// 大于号是升序，小于号是降序
    {
        largest = right;
    }
    if (largest != idx)
    {
        int temp = a[largest];
        a[largest] = a[idx];
        a[idx] = temp;
        Heapfy(a, largest, max);
    }
}
void buildHeap(int a[], int ll)
{
    int len = ll;
    for (int i = len / 2 - 1; i >= 0; --i) //第一次，将数据调整为堆
    {
        Heapfy(a, i, len);
    }
    for (int i = len - 1; i >= 1; --i)   // 利用堆进行排序
    {
        int temp = a[0];
        a[0] = a[i];
        a[i] = temp;
        Heapfy(a, 0, i);
    }
}
int main()
{
    int a[] = { 1, 5, 8, 6, 6, 48, 23, 0, 4, 0 };
    int n = sizeof(a) / sizeof(a[0]);
    cout << n << endl;
    for (int i = 0; i < n; i++)
    {
        cout << a[i] << " ";
    }
    cout << endl;
    buildHeap(a, n);
    for (int i = 0; i < n; i++)
    {
        cout << a[i] << " ";
    }
    cout << endl;

    system("pause");
    return 0;
}