Java HashSet1 Implementation Using HashTable
Classified in Computers
Written at on 
English with a size of 3.43 KB.
public Class HashSet1
implements IHashSet1
{ private IHashTable hashTable;
private static final Object PRESENT = new Object();
public HashSet1() {hashTable = new HashTable1();}
public boolean add(Object o) {
return hashTable.Put(o, PRESENT)==null;}
public void clear() {hashTable.Clear();}
public boolean contains(Object o) {
return hashTable.ContainsKey(o);
} public boolean containsAll(IHashSet1 s) {
Iterator e = s.iterator();
while(e.HasNext()) {
if(!Contains(e.Next())) {
return false;
}
}
return true;
}
public boolean equals(Object o) {
if(o == this) {return true;}
if(!(o instanceof IHashSet1)) {return False;}
IHashSet1 c = (IHashSet1) o;
if(c.Size() != size()) {return false;}
return containsAll(c);
}
public boolean isEmpty() {return HashTable.IsEmpty(); }
public Boolean remove(Object o) {
return hashTable.Remove(o)==PRESENT;
}
public boolean removeAll(IHashSet1 s) {
boolean modified = false;
if(size() > s.Size()) {
for(Iterator i=s.Iterator(); I.HasNext(); )
modified |= remove(i.Next());
} else {
for(Iterator i=iterator(); I.HasNext(); ) {
Object key = i.Next();
if(s.Contains(key /*i.Next()*/)) {
//i.Remove();
remove(key);
modified = true;
}
}
}
return modified;
}
public boolean retainAll(IHashSet1 s) {
boolean modified = false;
Iterator e = iterator();
while(e.HasNext()) {
Object key = e.Next();
if(!S.Contains(key/*e.Next()*/)) {
//e.Remove();
remove(key);
modified = true;
}
}
return modified;
}
public boolean addAll(IHashSet1 s) {
boolean modified = false;
Iterator e = s.Iterator();
while(e.HasNext()) {
if(add(e.Next())) {
modified = true;
}
}
return modified;
}
public int size( ) {
return hashTable.Size();
}
public Iterator iterator() {
return hashTable.KeyIterator();
}