Heap sort:-
Heap sort is a popular and efficient sorting algorithm in computer programming.
Heap sort works by visualizing the elements of the array as a special kind of complete binary tree called a heap.
Heap sort program:
#include <iostream>
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 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);
}
}
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);
}
} /* function to print array of size n */
void printArray(int arr[], int n)
{
for (int i = 0; i < n; i++)
{
cout << arr[i] << " ";
}
cout << "\n";
}
int main()
{
int arr[] = {121, 10, 130, 57, 36, 17};
int n = sizeof(arr)/sizeof(arr[0]);
heapSort(arr, n);
cout << "Sorted array is \n";
printArray(arr, n);
}
