Set, HashSet and TreeSet

• Set - generic set of values with no duplicate elements

• TreeSet - set where elements are sorted

• HashSet - set where elements are not sorted. Faster than TreeSet, and is an implementation of a Set

  Example:

  import java.util.*;
  .
  .
  .
      int a[] = {5,2,12,34,42,9,0,-4};
   	Set<Integer> s = new HashSet<Integer>();
    	
  	for(int i:a){
          s.add(i);
      }
    	
  	TreeSet ts = new TreeSet<Integer>(s);
  	System.out.println(ts);
  

Find Maximum in a set

Set<Integer> s = new HasHSet<>();
.
.
int maximum = Collections.max(s);

Remove Element from Set

Set<Integer> s = new HashSet<>();
int maximum = Collections.max(s);
s.remove(maximum);

Other functions

Set<Integer> s = new HashSet<>();
int size = s.size();
boolean b = s.contains(50);