Binary search trees - Data Structures and Problem Solving Using Java - page 741

1 /**
2 * Construct an empty TreeSet.
3 */
4 public TreeSet( )
5 {
6 nullNode = new AANode<AnyType>( null, null, null );
7 nullNode.left = nullNode.right = nullNode;
8 nullNode.level = 0;
9 root = nullNode;
10 cmp = null;
11 }
12
13 /**
14 * Construct an empty TreeSet with a specified comparator.
15 */
16 public TreeSet( Comparator<? super AnyType> c )
17 { this( ); cmp = c; }
18
19 /**
20 * Construct a TreeSet from another SortedSet.
21 */
22 public TreeSet( SortedSet<AnyType> other )
23 { this( other.comparator( ) ); copyFrom( other ); }
24
25 /**
26 * Construct a TreeSet from any collection.
27 * Uses an O( N log N ) algorithm, but could be improved.
28 */
29 public TreeSet( Collection<? extends AnyType> other )
30 { this( ); copyFrom( other ); }
31
32 /**
33 * Return the comparator used by this TreeSet.
34 * @return the comparator or null if the default comparator is used.
35 */
36 public Comparator<? super AnyType> comparator( )
37 { return cmp; }
38
39 /**
40 * Copy any collection into a new TreeSet.
41 */
42 private void copyFrom( Collection<? extends AnyType> other )
43 {
44 clear( );
45 for( AnyType x : other )
46 add( x );
47 }
figure 19.69
Constructors and comparator method for TreeSet