treeset

Set: Unordered. Can not repeat elements.|--hashset: Data structure is a hash table. The thread is unsynchronized.The principle of guaranteeing element uniqueness is to infer whether the hashcode value of an element is the same.Assuming the same, the Equals method of the element continues to be inferred. Is true.|--treeset: The ability to sort elements in a set collection.The underlying data structure is a two-fork tree.The basis for guaranteeing eleme

180217_JAVA _ TreeSet stores classes containing multiple strings and sets sorting rules, The Person class is as follows: 1 class Person {2 　　String name;3 　　int age;4 　　String address;5 } The main is as follows: 1 import java.util.TreeSet; 2 3 public class Test{ 4 　　public static void main(String[] args){ 5 　　　　Person p1 = new Person("AA",18,"CN"); 6 　　　　Person p2 = new Person("BB",18,"JP"); 7 　　　　Person p3 = new Person("CC",18,"CN"); 8 9 　　　　

Import Java.util.Iterator;Import Java.util.TreeSet;/** Sort the numbers in a string* String str = "10,2,11,1,34,101,32";*/public class Demo7 {public static void Main (string[] args) {String str = "10 2 11 1 34 10132";TreeSet ts = new TreeSet ();string[] arr = Str.split ("");for (int i=0; iTs.add (Integer.parseint (Arr[i]));//Convert to shaping, the elements have a natural order}SYSTEM.OUT.PRINTLN (TS);Using

Set Interface There is no obvious order between multiple objects in the Set set. For details, refer to the API documentation (it can be seen how important it is to include the API documentation at any time), which is basically the same as the collection method. But the behavior is different (set cannot contain duplicate elements ).The Set set does not allow repeated elements because set judges that two objects are the same instead of using the = Operator, but based on the equals method. That is,

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Reprint Address: http://shmilyaw-hotmail-com.iteye.com/blog/1836431 Brief Introduction TreeMap and TreeSet are some of the more difficult data structures in Java collection classes. Unlike ordinary hashmap, the time complexity of ordinary hashmap elements is generally the range of O (1). In TreeMap, the operation complexity of an element is O (logn). Although TreeMap is not an advantage in terms of access to elements, its internal elements are sorted

"TreeSet Collection Usage Instance "TreeSet collection of red and black tree storage and removal (figure) "TreeSet" Add () method source code TreeSet Collection Usage Instances Packagecn.itcast_05;ImportJava.util.TreeSet;/** TreeSet: Ability to sort

/*1. When adding elements to TreeSet, if the elements themselves have the nature of the order, they are sorted by the nature of the element's natural order.2. When adding elements to TreeSet, if the element itself does not have a natural order, then the class that the element belongs to must implement the comparable interface, the elementThe comparison rule is defined on the CompareTo () method.3. If the Co

TreeSet and TreeMapRelationship between TreeSet and TreeMap: 1. TreeSet actually uses TreeMap to organize data, because an instance variable of the NavigableMap Public V put (K key, V value) {Entry The following figure shows a more intuitive display.First assignment: Store the value as the root node Final Entry // Use a custom Comparator to compare and

classTreeSet is the only implementation class for the SortedSet interface, and TreeSet ensures that the collection elements are in the sorted state. TreeSet supports two sorting methods, natural sorting and custom sorting, in which the natural sort is the default sorting method. The object that is added to the treeset should be the same class.TreeSet determines

Java Collection This piece is used more in the work, some things always forget, so record down here. TreeSet principle 1. Features TreeSet are used for sorting, you can specify a sequence in which the objects are stored in the order specified 2. How to use A. natural order (comparable) The Add () method of the