C#でヒープソートをする方法

public class HeapSort
{
    public static void Main(string[] args)
    {
        int[] array = { 64, 25, 12, 22, 11 };
        Console.WriteLine("Array before sorting:");
        PrintArray(array);
        HeapSortAlgorithm(array);
        Console.WriteLine("Array after sorting:");
        PrintArray(array);
    }

    public static void HeapSortAlgorithm(int[] arr)
    {
        int n = arr.Length;

        // Build a max heap
        for (int i = n / 2 - 1; i >= 0; i--)
        {
            Heapify(arr, n, i);
        }

        // Extract elements from the heap in descending order
        for (int i = n - 1; i > 0; i--)
        {
            // Move current root (maximum element) to the end
            int temp = arr[0];
            arr[0] = arr[i];
            arr[i] = temp;

            // Max heapify the reduced heap
            Heapify(arr, i, 0);
        }
    }

    public static void Heapify(int[] arr, int n, int root)
    {
        int largest = root;
        int leftChild = 2 * root + 1;
        int rightChild = 2 * root + 2;

        // If left child is larger than root
        if (leftChild < n && arr[leftChild] > arr[largest])
        {
            largest = leftChild;
        }

        // If right child is larger than largest so far
        if (rightChild < n && arr[rightChild] > arr[largest])
        {
            largest = rightChild;
        }

        // If largest is not the root
        if (largest != root)
        {
            int swap = arr[root];
            arr[root] = arr[largest];
            arr[largest] = swap;

            // Recursively heapify the affected sub-tree
            Heapify(arr, n, largest);
        }
    }

    public static void PrintArray(int[] arr)
    {
        int n = arr.Length;
        for (int i = 0; i < n; ++i)
        {
            Console.Write(arr[i] + " ");
        }
        Console.WriteLine();
    }
}