HeapSort.cpp

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

void heapify(int arr[], int n, int i) {
    int largest = i;
    int left = 2 * i + 1;
    int right = 2 * i + 2;
    if (left < n && arr[left] > arr[largest])
        largest = left;
    if (right < n && arr[right] > arr[largest])
        largest = right;
    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 n;
    cout << "Enter number of elements: ";
    cin >> n;
    int * arr = new int(n);
    cout << "Enter elements: ";
    for (int i = 0; i < n; ++i)
        cin >> arr[i];
    heapSort(arr, n);
    cout << "\nSorted array is: ";
    printArray(arr, n);
}