Heap_sort.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);
    }
}


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


int main()
{
    int arr[1000],n ;

   cout<<"Enter the number of elements: ";
   cin>>n;
   cout<<"Enter the elements: ";
   for(int i=0;i<n;i++){
    cin>>arr[i];
   }

    heapSort(arr, n);

    cout << "Sorted array is \n";
    printArray(arr, n);
}