Question

implement heap sort algorithm continuing off this

#include <iostream>
#define MAX_INT 2147483647
using namespace std;

int main(int argc,char **argv) {

int* array;
int arraySize = 1;

// Get the size of the sequence
cin >> arraySize;
array = new int[arraySize];

// Read the sequence
for(int i=0; i<arraySize; i++){

cin >> array[i];

}

Answer 1

#include <iostream>
#define MAX_INT 2147483647
using namespace std;
void heapify(int arr[], int n, int i)
{
int largest = i; // Initialize largest as root
int l = 2 * i + 1; // left = 2*i + 1
int r = 2 * i + 2; // right = 2*i + 2
  
// If left child is larger than root
if (l < n && arr[l] > arr[largest])
largest = l;
  
// If right child is larger than largest so far
if (r < n && arr[r] > arr[largest])
largest = r;
  
// If largest is not root
if (largest != i) {
swap(arr[i], arr[largest]);
  
// Recursively heapify the affected sub-tree
heapify(arr, n, largest);
}
}
  
// main function to do heap sort
void heapSort(int arr[], int n)
{
// Build heap (rearrange array)
for (int i = n / 2 - 1; i >= 0; i--)
heapify(arr, n, i);
  
// One by one extract an element from heap
for (int i = n - 1; i >= 0; i--) {
// Move current root to end
swap(arr[0], arr[i]);
  
// call max heapify on the reduced heap
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 argc,char **argv) {

int* array;
int arraySize = 1;

// Get the size of the sequence
cout <<"Enter arrayszie: ";
cin >> arraySize;
array = new int[arraySize];

// Read the sequence
cout<<"Enter elements: ";
for(int i=0; i<arraySize; i++)
   cin >> array[i];
cout<<"Array Before Sorting: ";
printArray(array,arraySize);
heapSort(array,arraySize);
cout<<"Array After Sorting: ";
printArray(array,arraySize);
}

/* OUTPUT */

/* PLEASE UPVOTE */