treeset

One Class A day, not a bit tired.Now it's about---TreeSet.TreesetTo tell you the truth, I haven't used this *_*.--"a NavigableSet implementation based on a TreeMap ." The elements is ordered using their natural ordering, or by a Comparator provided at set creation time, depending on which con Structor is used.As above, the TreeSet implements the Navigableset, which requires that the elements are sorted in natural order or using the comparator comparer

/*treeset* TreeSet automatically calls the element's CompareTo (Object obj) method after the data is stored and automatically sorts the data* So the output data is sorted data* Note: The return value of the CompareTo method is: Negative, 0, positive. Represent less than, equal to, greater than* CompareTo (Object obj) method to override element for storing custom object elements* When defining an element, yo

1.TreeSet principle:/** TreeSet can be sorted when storing objects, but it is necessary to specify an algorithm for sorting** Integer can be sorted (with default order), string can be sorted (with default order), the custom class is stored with an exception (no order)** If you want to sort the objects of a custom class into TreeSet, you must implement the compara

this way, the elements seem to be saved in the order of insertion. That is to say, when traversing the elements in the linkedhashset set, it will access the elements in the set in the order of element addition. Therefore, the performance of linkedhashset is slightly lower than that of hashset, but it will have good performance when accessing all elements iteratively, because it maintains the internal order by using a linked list. Ii. treeset

Like HashSet implementation based on HashMap, TreeSet is also implemented based on TreeMap. In Java enhancement () ----- TreeMap, LZ explains the TreeMap implementation mechanism in detail. If you read this blog post or learn more about TreeMap, therefore, the implementation of TreeSet is as simple as drinking water.I. TreeSet Definition We know that TreeMap is a

Let's take a look at the operation of set map today, so we start with the codeVal data = mutable. Set.empty[int]Data ++= list (+/-)//Add to table on empty setData + = 4//Add new element to setData--= List (2,3)println (data)//set (1, 4)Data + = 1println (data)//set (1, 4), stating that the Set element cannot be duplicatedData.clear ()println (data)//set ()We can see that the set and list operations are roughly the same, but the important difference is that there are no duplicate elements in the

The set set is a subset of collection, and the set set is basically the same as collection, without providing any additional methods, except that the set does not allow repeating elements.Set set of 3 implementation classes: HashSet, TreeSet, Enumset　　First, HashSet Public class Hashsetextends abstractsetimplements SetHashSet is a typical implementation of the set interface, and HashSet stores the elements by the hash algorithm, so it has good access

The main reason for using set collections is because there are no duplicate elements in the set collection. The set collection has three common implementation classes: Hashset,treeset,linkedhashset. When to choose which one to use is very important. Simply put, if you focus on performance, you should use hashset; If you need an ordered set of sets, you should use TreeSet if you need a set collection to save

Java container --- Set: HashSet TreeSet LinkedHashSet, --- sethashset1. Set interface Overview SetDo not save repeated elements (how to determine if the elements are the same ?). If you try to add multiple instances of the same object to the Set, it will block this repetition. The most common use of Set is test normalization. You can easily ask whether an object is in a Set. Because of this, searching becomes the most important operation in the Set,

The relationship between TreeSet and TreeMap: 1. TreeSet actually uses treemap to organize the data, because a navigablemap 2. Both TreeSet and treemap use binary tree data structures to store The data saved in 3.TreeSet and TreeMap requires the implementation of the comparable interf

The collection package is the most commonly used package in Java, and it is most commonly used with implementation classes for collection and map two interfaces, where collection is used to hold multiple single objects, and map is used to store key-value pairs in key-value form. There are two types of interfaces commonly used in collection: List and set, the most obvious difference is that the list supports placing duplicate objects, and set does not support. The list interface commonly used imp

First Lecture TreeSet1. OverviewTreeSet can sort the elements in the set set, in natural order.2. Demo CodeOutput Result:Summary: TreeSet will sort the elements naturally, with uppercase in front of lowercase.Second lecture TreeSet storing a custom object1. Overview:Stores the custom object in the TreeSet collection.2, ideas:Customize student classes and store st

1.TreeSet principle:/** TreeSet can be sorted when storing objects, but it is necessary to specify an algorithm for sorting* * Integer can be sorted (with default order), string can be sorted (with default order), the custom class is stored with an exception (no order)* * If you want to sort the objects of a custom class into TreeSet, you must implement the compa