我可能很快就会教“ Java速成课程”。虽然可以很安全地假设受众成员知道Big-O表示法,但是假设他们将知道各种集合实现上的各种操作的顺序可能是不安全的。
我可能会花一些时间自己生成一个摘要矩阵,但是如果它已经存在于公共领域中的某个地方,我肯定会重用它(当然要有适当的信誉)。
有人有指针吗?
有人有指针吗?列出实现:
get add contains next remove(0) iterator.remove ArrayList O(1) O(1) O(n) O(1) O(n) O(n) LinkedList O(n) O(1) O(n) O(1) O(1) O(1) CopyOnWrite-ArrayList O(1) O(n) O(n) O(1) O(n) O(n)
设置实现:
add contains next notes HashSet O(1) O(1) O(h/n) h is the table capacity LinkedHashSet O(1) O(1) O(1) CopyOnWriteArraySet O(n) O(n) O(1) EnumSet O(1) O(1) O(1) TreeSet O(log n) O(log n) O(log n) ConcurrentSkipListSet O(log n) O(log n) O(1)
地图实现:
get containsKey next Notes HashMap O(1) O(1) O(h/n) h is the table capacity LinkedHashMap O(1) O(1) O(1) IdentityHashMap O(1) O(1) O(h/n) h is the table capacity EnumMap O(1) O(1) O(1) TreeMap O(log n) O(log n) O(log n) ConcurrentHashMap O(1) O(1) O(h/n) h is the table capacity ConcurrentSkipListMap O(log n) O(log n) O(1)
队列实现:
offer peek poll size PriorityQueue O(log n) O(1) O(log n) O(1) ConcurrentLinkedQueue O(1) O(1) O(1) O(n) ArrayBlockingQueue O(1) O(1) O(1) O(1) LinkedBlockingQueue O(1) O(1) O(1) O(1) PriorityBlockingQueue O(log n) O(1) O(log n) O(1) DelayQueue O(log n) O(1) O(log n) O(1) LinkedList O(1) O(1) O(1) O(1) ArrayDeque O(1) O(1) O(1) O(1) LinkedBlockingDeque O(1) O(1) O(1) O(1)