014_HeapSort.cpp

#include <bits/stdc++.h>
using namespace std;

void heapify(int arr[], int N, int i)
{
    int largest = i;
    int l = 2 * i + 1;
    int r = 2 * i + 2;
    if (l < N && arr[l] > arr[largest])
        largest = l;
    if (r < N && arr[r] > arr[largest])
        largest = r;
    if (largest != i)
    {
        swap(arr[i], arr[largest]);
        heapify(arr, N, largest);
    }
}

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

    for (int i = N / 2 - 1; i >= 0; i--)
        heapify(arr, N, i);
    for (int i = N - 1; i > 0; i--)
    {
        swap(arr[0], arr[i]);
        heapify(arr, i, 0);
    }
}

int main()
{
    int A[] = {2, 5, 7, 1, 2, 3, 5, 7};
    int n = sizeof(A) / sizeof(int);
    heapSort(A, n);
    cout << "After Sorting:" << endl;
    for (int i = 0; i < n; i++)
    {
        cout << A[i] << endl;
    }
    return 0;
}