#include <iostream>
using namespace std;

void HeapSort(int number[], int n);
void MaxHeap(int number[], int n, int i);
void Print(int number[], int n);

int main()
{
	int n, i;
	cout<<"Enter the number of data element to be sorted: ";
	cin>>n;

	int data[n];
	for(i = 0; i < n; i++)
	{
		cout<<"Enter element "<<i+1<<": ";
		cin>>data[i];
	}

    cout<<endl<<"BEFORE SORTED : ";
	Print(data, n);

	HeapSort(data, n);

	cout<<"AFTER SORTED : ";
	Print(data, n);
	return 0;
}

void MaxHeap(int number[], int n, int i)
{
    int t;
    int largest = i;
    int l = 2*i + 1;
    int r = 2*i + 2;

    if (l < n && number[l] > number[largest])
    {
        largest = l;
    }

    if (r < n && number[r] > number[largest])
    {
        largest = r;
    }

    if (largest != i)
    {
        t = number[i];
        number[i] = number[largest];
        number[largest] = t;

        MaxHeap(number, n, largest);
    }
}

void HeapSort(int number[], int n)
{
    int t;

    for (int i = n / 2 - 1; i >= 0; i--)
    {
        MaxHeap(number, n, i);
    }

    for (int i=n-1; i>=0; i--)
    {
        t = number[0];
        number[0] = number[i];
        number[i] = t;

        MaxHeap(number, i, 0);
    }
}

void Print(int number[], int n)
{
    for (int i=0; i<n; ++i)
    {
        cout << number[i] << " ";
    }
    cout <<endl;
}