jwutil.collections
Class SetUtil

java.lang.Object
  jwutil.collections.SetUtil

public abstract class SetUtil
extends java.lang.Object

SetUtil

Version:

$Id: SetUtil.java 1934 2004-09-27 22:42:35Z joewhaley $

Author:

John Whaley

Constructor Summary

SetUtil()

Method Summary

static java.util.Collection	powerSet(java.util.Collection c) The powerSet method returns a Collection whose elements are exactly the subsets of c, with no repetitions.
static java.util.Collection	powerSet(CollectionFactory f, java.util.Collection c) The powerSet method returns a Collection whose elements are exactly the subsets of c, with no repetitions.
static java.util.Collection	uniquify(java.util.Collection c) Given an input Collection that may contain duplicates returns a Collection with the same elements but no duplicates.
static java.util.Collection	uniquify(CollectionFactory f, java.util.Collection c) Given an input Collection that may contain duplicates returns a Collection with the same elements but no duplicates.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SetUtil

public SetUtil()

Method Detail

powerSet

public static java.util.Collection powerSet(java.util.Collection c)

The powerSet method returns a Collection whose elements are exactly the subsets of c, with no repetitions. More precisely, if c is a Collection, possibly with repetitions, the result powerSet(c) is a Collection u without repetitions whose elements represent all the subsets of v. The powerset is stored in an ArrayList.

Parameters:

c - collection to take powerset of

Returns:

powerset of the given collection

See Also:

ArrayList, powerSet(CollectionFactory,Collection)

powerSet

public static java.util.Collection powerSet(CollectionFactory f,
                                            java.util.Collection c)

The powerSet method returns a Collection whose elements are exactly the subsets of c, with no repetitions. More precisely, if c is a Collection, possibly with repetitions, the result powerSet(c) is a Collection u without repetitions whose elements represent all the subsets of v.

Parameters:

f - collection factory to use to generate collection

c - collection to take powerset of

Returns:

powerset of the given collection

uniquify

public static java.util.Collection uniquify(java.util.Collection c)

Given an input Collection that may contain duplicates returns a Collection with the same elements but no duplicates. The resulting is returned in an ArrayList.

Parameters:

c - collection to uniquify

Returns:

uniquified version of collection

See Also:

ArrayList, uniquify(CollectionFactory,Collection)

uniquify

public static java.util.Collection uniquify(CollectionFactory f,
                                            java.util.Collection c)

Given an input Collection that may contain duplicates returns a Collection with the same elements but no duplicates. If c is already a Set, we just return a clone of it.

Parameters:

f - collection factory to use to generate collection

c - collection to uniquify

Returns:

uniquified version of collection