| | | Indexed Set |
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//package gr.forth.ics.util;
import java.util.AbstractCollection;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
/**
*
* @author Andreou Dimitris, email: jim.andreou (at) gmail (dot) com
*/
public class IndexedSet<T> extends AbstractCollection<T> implements Set<T> {
private final List<T> list = new ArrayList<T>();
private final Set<T> set = new HashSet<T>();
public int size() {
return list.size();
}
@Override
public boolean isEmpty() {
return list.isEmpty();
}
@Override
public boolean contains(Object o) {
return set.contains(o);
}
public Iterator<T> iterator() {
return new Iterator<T>() {
Iterator<T> realIterator = list.iterator();
T current = null;
public boolean hasNext() {
return realIterator.hasNext();
}
public T next() {
T next = realIterator.next();
current = next;
return next;
}
public void remove() {
realIterator.remove();
set.remove(current);
current = null;
}
};
}
@Override
public Object[] toArray() {
return list.toArray();
}
@Override
public <T> T[] toArray(T[] a) {
return list.toArray(a);
}
@Override
public boolean add(T e) {
boolean added = set.add(e);
if (added) {
list.add(e);
}
return added;
}
@Override
public boolean remove(Object o) {
boolean removed = set.remove(o);
if (removed) {
list.remove(o);
}
return removed;
}
@Override
public boolean containsAll(Collection<?> c) {
return set.containsAll(c);
}
@Override
public boolean retainAll(Collection<?> c) {
boolean removed = false;
Iterator<T> it = list.iterator();
while (it.hasNext()) {
T next = it.next();
if (!c.contains(next)) {
it.remove();
set.remove(it);
removed = true;
}
}
return removed;
}
public void clear() {
set.clear();
list.clear();
}
public T get(int index) {
return list.get(index);
}
public T remove(int index) {
T t = list.get(index);
remove(t);
return t;
}
}
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| Related examples in the same category |
| 1. | Set, HashSet and TreeSet | | | | 2. | Things you can do with Sets | |  | | 3. | Set operations: union, intersection, difference, symmetric difference, is subset, is superset | | | | 4. | Set implementation that use == instead of equals() | | | | 5. | Set that compares object by identity rather than equality | | | | 6. | Set union and intersection | | | | 7. | Set with values iterated in insertion order. | | | | 8. | Putting your own type in a Set | |  | | 9. | Use set | |  | | 10. | Another Set demo | | | | 11. | Set subtraction | |  | | 12. | Working with HashSet and TreeSet | |  | | 13. | TreeSet Demo | |  | | 14. | Show the union and intersection of two sets | | | | 15. | Demonstrate the Set interface | | | | 16. | Array Set extends AbstractSet | |  | | 17. | Sync Test | | | | 18. | Set Copy | | | | 19. | Set and TreeSet | | | | 20. | Tail | | | | 21. | What you can do with a TreeSet | |  | | 22. | Remove all elements from a set | | | | 23. | Copy all the elements from set2 to set1 (set1 += set2), set1 becomes the union of set1 and set2 | | | | 24. | Remove all the elements in set1 from set2 (set1 -= set2), set1 becomes the asymmetric difference of set1 and set2 | | | | 25. | Get the intersection of set1 and set2, set1 becomes the intersection of set1 and set2 | | | | 26. | Extend AbstractSet to Create Simple Set | | | | 27. | Int Set | | | | 28. | One Item Set | | | | 29. | Small sets whose elements are known to be unique by construction | | | | 30. | List Set implements Set | | | | 31. | Converts a char array to a Set | | | | 32. | Converts a string to a Set | | | | 33. | Implements the Set interface, backed by a ConcurrentHashMap instance | | | | 34. | An IdentitySet that uses reference-equality instead of object-equality | | | | 35. | An implementation of the java.util.Stack based on an ArrayList instead of a Vector, so it is not synchronized to protect against multi-threaded access. | | | | 36. | A thin wrapper around a List transforming it into a modifiable Set. | | | | 37. | A thread-safe Set that manages canonical objects | | | | 38. | This program uses a set to print all unique words in System.in | | | | 39. | Indexed Set | | | | 40. | An ObjectToSet provides a java.util.Map from arbitrary objects to objects of class java.util.Set. | | | | 41. | Sorted Multi Set | | | | 42. | Fixed Size Sorted Set | | | | 43. | Set operations | | | | 44. | A NumberedSet is a generic container of Objects where each element is identified by an integer id. | | | | 45. | Set which counts the number of times a values are added to it. | | | | 46. | Set which counts the number of times a values are added to it and assigns them a unique positive index. | | | | 47. | A set acts like array. | | | | 48. | Implements a Bloom filter. Which, as you may not know, is a space-efficient structure for storing a set. | | | | 49. | Implementation of disjoint-set data structure | | | | 50. | Call it an unordered list or a multiset, this collection is defined by oxymorons | | |
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