MaxRevenueTickets.java

import java.util.Comparator;
import java.util.PriorityQueue;

public class MaxRevenueTickets {

	PriorityQueue<Integer> pq;

	// we will create a max heap
	public MaxRevenueTickets(int length) {
		pq = new PriorityQueue<>(length, new Comparator<Integer>() {

			@Override
			public int compare(Integer o1, Integer o2) {
				// TODO Auto-generated method stub
				return o2 - o1;
			}
		});
	}

	public int calculate(int[] windowsTickets, int tickets) {

		int revenue = 0;
		// insert the all the elements of an array into the priority queue
		for (int i = 0; i < windowsTickets.length; i++) {
			pq.offer(windowsTickets[i]);
		}

		while (tickets > 0) {
			int ticketPrice = pq.poll();
			revenue += ticketPrice;
			pq.offer(--ticketPrice);
			tickets--;
		}
		return revenue;
	}

	public static void main(String[] args) {
		int[] windowsTickets = { 5, 1, 7, 10, 11, 9 };
		int noOfTickets = 5;
		MaxRevenueTickets mx = new MaxRevenueTickets(windowsTickets.length);
		System.out.println("Max revenue generated by selling " + noOfTickets
				+ " tickets: " + mx.calculate(windowsTickets, noOfTickets));

	}
}