java 优先级队列示例2017-06-19

Posted 2021-05-08

package bearcola.queue.priorityqueue;

import java.util.PriorityQueue;

public class Top10 {
	static PriorityQueue<Integer> q = new PriorityQueue<Integer>();
	
	public static void main(String[] args) {
		
		for (int i=0; i<100; i++) {
			read(i);
		}
		
		int[] result = getTop10();
		
		for (int item: result) {
			System.out.println(item);
		}
	}
	
	public static void read(int n) {
		if (q.size() < 10) {
			q.offer(n);
		} else {
			int tenth = q.peek();
			if (n > tenth) {
				q.poll();
				q.offer(n);
			}
		}
	}
	
	public static int[] getTop10() {
		int[] ret = new int[q.size()];
		for (int i=q.size()-1; i>=0; i--) {
			ret[i] = q.poll();
		}
		return ret;
	}

}