java 优先队列 PriorityQueue
代码:
PriorityQueue<Integer> pq = new PriorityQueue<>((x, y) -> y - x); for (int i = 1; i <= 5; i++) { pq.add(i); System.out.println( pq.toString()); }
输出:
[1]
[2, 1]
[3, 1, 2]
[4, 3, 2, 1]
[5, 4, 2, 1, 3]
(由于PriorityQueue通过二叉小顶堆实现,所以toString打印输出的其实二叉树结构)