Main.java

package org.example;

//max heap data structure
//By Samuel Waweru
// For Walmart USA Virtual Experience
public class Main {
    static 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) {
            int swap = arr[i];
            arr[i] = arr[largest];
            arr[largest] = swap;
            heapify(arr, N, largest);
        }
    }
        static void buildHeap(int arr[], int N)
        {
            // Index of last non-leaf node
            int startIdx = (N / 2) - 1;
            // Perform reverse level order traversal
            // from last non-leaf node and heapify
            // each node
            for (int i = startIdx; i >= 0; i--) {
                heapify(arr, N, i);
            }
        }
        static void printHeap(int arr[], int N)
        {
            System.out.println("Array representation of Heap is:");
            for (int i = 0; i < N; ++i)
                System.out.print(arr[i] + " ");
            System.out.println();
        }
    // Driver Code
    public static void main(String args[])

    {
        int heap_priority[] = {1, 3, 5, 4, 6, 13};
        int No_of_customers = heap_priority.length;
        buildHeap(heap_priority, No_of_customers);
        printHeap(heap_priority, No_of_customers);

    }



}