what is a heap sort code example

Example 1: heap sort

# Heap Sort in python


  def heapify(arr, n, i):
      # Find largest among root and children
      largest = i
      l = 2 * i + 1
      r = 2 * i + 2
  
      if l < n and arr[i] < arr[l]:
          largest = l
  
      if r < n and arr[largest] < arr[r]:
          largest = r
  
      # If root is not largest, swap with largest and continue heapifying
      if largest != i:
          arr[i], arr[largest] = arr[largest], arr[i]
          heapify(arr, n, largest)
  
  
  def heapSort(arr):
      n = len(arr)
  
      # Build max heap
      for i in range(n//2, -1, -1):
          heapify(arr, n, i)
  
      for i in range(n-1, 0, -1):
          # Swap
          arr[i], arr[0] = arr[0], arr[i]
  
          # Heapify root element
          heapify(arr, i, 0)
  
  
  arr = [1, 12, 9, 5, 6, 10]
  heapSort(arr)
  n = len(arr)
  print("Sorted array is")
  for i in range(n):
      print("%d " % arr[i], end='')

Example 2: Heap Sort

class Sort {
    public void heapSort(int arr[])
    {
        int temp;
 
        for (int i = arr.length / 2 - 1; i >= 0; i--)                //build the heap
        {
            heapify(arr, arr.length, i);
        }
 
        for (int i = arr.length - 1; i > 0; i--)                            //extract elements from the heap
        {
            temp = arr[0];                                                  //move current root to end (since it is the largest)
            arr[0] = arr[i];
            arr[i] = temp;
            heapify(arr, i, 0);                                             //recall heapify to rebuild heap for the remaining elements
        }
    }
 
    void heapify(int arr[], int n, int i)
    {
        int MAX = i; // Initialize largest as root
        int left = 2 * i + 1; //index of the left child of ith node = 2*i + 1
        int right = 2 * i + 2; //index of the right child of ith node  = 2*i + 2
        int temp;

        if (left < n && arr[left] > arr[MAX])            //check if the left child of the root is larger than the root
        {
            MAX = left;
        }
 
        if (right < n && arr[right] > arr[MAX])            //check if the right child of the root is larger than the root
        {
            MAX = right;
        }
 
        if (MAX != i) 
        {                                               //repeat the procedure for finding the largest element in the heap
            temp = arr[i];
            arr[i] = arr[MAX];
            arr[MAX] = temp;
            heapify(arr, n, MAX);
        }
    }
 
    void display(int arr[])                 //display the array
    {  
        for (int i=0; i<arr.length; ++i) 
        {
            System.out.print(arr[i]+" ");
        } 
    } 
 
    public static void main(String args[])
    {
        int arr[] = { 1, 12, 9 , 3, 10, 15 };
 
        Sort ob = new Sort();
        ob.heapSort(arr);
        ob.display(arr);
    }
}