package tests;

import java.util.*;

/**
 * Shows how to use priority queues with custom comparators.
 *
 * Created with IntelliJ IDEA.
 * User: Marek Grzes
 * Date: 15/11/12 11:13 AM
 */
public class PQ {
	static class Data {
		public int first;
		public int second;
	}

	public static void main(String[] args) {

		Comparator<Data> comparator = new Comparator<Data>(){
			@Override
			public int compare(final Data o1, final Data o2){
				// for smaller values having higher priority
				if ( o1.second > o2.second ) return 1;
				else if ( o1.second < o2.second ) return -1;
				return 0;
			}
		};

		Random generator = new Random();

		int initialCapacity = 10;
		PriorityQueue<Data> pq = new PriorityQueue<Data>(initialCapacity, comparator);

		for ( int a = 0; a < 10; a++ ) {
			Data tmp = new Data();
			tmp.first = generator.nextInt() % 1000;
			tmp.second = generator.nextInt() % 1000;
			pq.add(tmp);
		}

		System.out.println("all data:");
		Iterator<Data> iter = pq.iterator();
		while (iter.hasNext()) {
			Data tmp = iter.next();
			System.out.println(tmp.first + " " + tmp.second);
		}

		Data best = pq.peek();
		System.out.println("the best element: (" + best.first + ", " + best.second + ")");

		System.out.println("prioritised data:");
		Data tmp = pq.poll();
		while ( tmp != null ) {
			System.out.println(tmp.first + " " + tmp.second);
			tmp = pq.poll();
		}

	}
}