treeset

I'd like to have list of object sorted with property 'sort_1'. But when I want to remove I'd like it to use property 'id'. The following code represents the problem. package javaapplication1; import java.util.TreeSet; public class MyObj implements Comparable<MyObj> { public long sort_1; public long id; public MyObj(long sort, long id) { this.sort_1=sort; this.id=id; } @Override public int compareTo(MyObj other) { int ret = Long.compare(sort_1, other.sort_1); return ret; } public String toString() { return id+":"+sort_1; } public static void main(String[] args) { TreeSet<MyObj> lst=new TreeSet

Is the computational complexity of TreeSet methods in Java, same as that of an AVLTree? Specifically, I want to know the computational complexity of the following methods: 1.add 2.remove 3.first 4.last 5. floor 6. higher Java Doc for method description: http://docs.oracle.com/javase/6/docs/api/java/util/TreeSet.html For an AVL Tree, there are all O(logn)? Whats the complexity of the above TreeSet Methods? Operations which work on a single element are all O(ln n) comparisons except first and last which are O(1) comparisons or O(ln N) node search time. comparator(), iterator(), clear(), first(),

It came to my notice that a TreeSet doesn't keep the mutable objects in sorted order if object attribute values are changed later on. For example, public class Wrap { static TreeSet<Student> ts = new TreeSet<Student>(new Comparator<Student>(){ @Override public int compare(Student o1, Student o2) { return o1.age - o2.age; } }); public static void main(String []args){ Student s = new Student(10); ts.add(s); ts.add(new Student(50)); ts.add(new Student(30)); ts.add(new Student(15)); System.out.println(ts); s.age = 24; //Here I change the age of a student in the TreeSet System.out.println(ts); } }