PriorityQueue 的用法
PriorityQueue
是一种数据结构。与 SortedSet
一样,PriorityQueue
也根据其优先级对其元素进行排序。具有较高优先级的元素首先出现。PriorityQueue
的类型应该实现 comparable
或 comparator
接口,其方法决定数据结构元素的优先级。
//The type of the PriorityQueue is Integer.
PriorityQueue<Integer> queue = new PriorityQueue<Integer>();
//The elements are added to the PriorityQueue
queue.addAll( Arrays.asList( 9, 2, 3, 1, 3, 8 ) );
//The PriorityQueue sorts the elements by using compareTo method of the Integer Class
//The head of this queue is the least element with respect to the specified ordering
System.out.println( queue ); //The Output: [1, 2, 3, 9, 3, 8]
queue.remove();
System.out.println( queue ); //The Output: [2, 3, 3, 9, 8]
queue.remove();
System.out.println( queue ); //The Output: [3, 8, 3, 9]
queue.remove();
System.out.println( queue ); //The Output: [3, 8, 9]
queue.remove();
System.out.println( queue ); //The Output: [8, 9]
queue.remove();
System.out.println( queue ); //The Output: [9]
queue.remove();
System.out.println( queue ); //The Output: []