Java优先队列

package structure;

import java.util.Iterator;
import java.util.PriorityQueue;
import java.util.Queue;

/**
 * Java中的优先队列使用
 * @author Dreamy
 *
 */
public class PriorityQueueDemo {
    /**
     * @param args
     */
    public static void main(String[] args) {
        //Java中的PriorityQueue 默认排序方式为自然顺序
        int[] numbers = {4,5,2,1,9,6,8,7};
        findTopK(numbers);
    }

    //找出数组中top k大
    private static void findTopK(int[] numbers) {
        
        Queue<Integer> queue = new PriorityQueue<Integer>();
    
        final int k = 3;
        for(int i=0;i<k;i++)
            queue.add(numbers[i]);
        
        for(int i=k;i<numbers.length;i++){
            int min = queue.peek();
            if(numbers[i]>min){
                queue.poll();
                queue.offer(numbers[i]);
            }
        }
        
        Iterator<Integer> itr = queue.iterator();
        while(itr.hasNext()){
            int num = itr.next();
            System.out.println(num);
        }
    }

}