org.jamesframework.core.subset.algo.exh

Class SubsetSolutionIterator

java.lang.Object

org.jamesframework.core.subset.algo.exh.SubsetSolutionIterator

All Implemented Interfaces:

SolutionIterator<SubsetSolution>

public class SubsetSolutionIterator
extends Object
implements SolutionIterator<SubsetSolution>

A subset solution iterator generates all possible subsets within a given size range, given a set of IDs from which to select. It can be plugged into an exhaustive search algorithm to generate and evaluate all possible subset solutions.

A SubsetIterator is used internally and selected items are wrapped in a subset solution.

Author:

Herman De Beukelaer

Constructor Summary

Constructors

Constructor and Description
SubsetSolutionIterator(Set<Integer> IDs, int fixedSubsetSize) Create a subset solution iterator that generates all subsets with a fixed size, sampled from the given set of IDs.
SubsetSolutionIterator(Set<Integer> IDs, int minSubsetSize, int maxSubsetSize) Create a subset solution iterator that generates all subsets within the given size range, sampled from the given set of IDs.

Method Summary

Modifier and Type	Method and Description
boolean	hasNext() Checks whether more subset solutions are to be generated.
SubsetSolution	next() Generate the next subset solution.

Methods inherited from class java.lang.Object

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

Constructor Detail

SubsetSolutionIterator

public SubsetSolutionIterator(Set<Integer> IDs,
                              int minSubsetSize,
                              int maxSubsetSize)

Create a subset solution iterator that generates all subsets within the given size range, sampled from the given set of IDs.

Parameters:

IDs - set of IDs to select from

minSubsetSize - minimum subset size

maxSubsetSize - maximum subset size

Throws:

NullPointerException - if IDs is null

IllegalArgumentException - if IDs is empty, minSubsetSize < 0, minSubsetSize > |IDs|, or minSubsetSize > maxSubsetSize

SubsetSolutionIterator

public SubsetSolutionIterator(Set<Integer> IDs,
                              int fixedSubsetSize)

Create a subset solution iterator that generates all subsets with a fixed size, sampled from the given set of IDs.

Parameters:

IDs - set of IDs to select from

fixedSubsetSize - fixed subset size

Throws:

NullPointerException - if IDs is null

IllegalArgumentException - if IDs is empty, fixedSubsetSize < 0, or fixedSubsetSize > |IDs|

Method Detail

hasNext

public boolean hasNext()

Checks whether more subset solutions are to be generated.

Specified by:

hasNext in interface SolutionIterator<SubsetSolution>

Returns:

true if not all possible subsets of all valid size have already been generated

next

public SubsetSolution next()

Generate the next subset solution. The returned subset will either have the same size as the previously generated solution, if any, or it will be a larger subset.

Specified by:

next in interface SolutionIterator<SubsetSolution>

Returns:

next subset solution within the size bounds

Throws:

NoSuchElementException - if there is no next solution to be generated