修复 HeapSort - 奇怪的时间

如何解决修复 HeapSort - 奇怪的时间

这个程序能很好地测量时间吗？因为我有非常奇怪的结果，当“n”有 1 000 000 个元素时，时间是 0.06，但我确定它太快了。问题出在哪儿？在 QSort (pivot - 3 的中位数和元素 = rand()%100) 我有 97810 毫秒......这是什么原因？代码中是否有遗漏或错误？

#include <iostream>
#include <ctime>

using namespace std;
const int n = 100000;

void heapify(int arr[],int n,int root)
{
    int largest = root; 
    const int left = 2 * root + 1;
    const int right = left + 1; 

    if (left < n && arr[left] > arr[largest])
        largest = left;

    if (right < n && arr[right] > arr[largest])
        largest = right;

    if (largest != root) {
        swap(arr[root],arr[largest]);

        heapify(arr,n,largest);
    }
}

void heapSort(int arr[],int n)
{

    for (int i = n / 2 - 1; i >= 0; i--)
        heapify(arr,i);

    for (int i = n - 1; i >= 0; i--) {
        swap(arr[0],arr[i]);

        heapify(arr,i,0);
    }
}

void printArray(int arr[],int n)
{
    for (int i = 0; i < n; ++i)
        cout << arr[i] << " ";
    cout << "\n";
}

int main()
{
    int *arr = new int[n];
    for(int i = 0; i< n; i++)
        arr[i] = rand()%100;
 //   cout << "Not-Sorted array is "<<endl<<endl;
 //   printArray(arr,n);
    cout<<endl;

    const auto start = clock();
    heapSort(arr,n);
    const auto stop = clock();
    const auto time = static_cast<double>(stop - start) / CLOCKS_PER_SEC;

//    cout << "Sorted array is "<<endl<<endl;
 //   printArray(arr,n);

    cout<<endl<< "Time is : "<<time<<endl<<endl;
}