org.jamesframework.core.search.neigh

Interface Neighbourhood<SolutionType extends Solution>

Type Parameters:

SolutionType - solution type for which this neighbourhood can be applied, required to extend Solution

All Known Implementing Classes:

DisjointMultiAdditionNeighbourhood, DisjointMultiDeletionNeighbourhood, DisjointMultiSwapNeighbourhood, MultiAdditionNeighbourhood, MultiDeletionNeighbourhood, MultiSwapNeighbourhood, SingleAdditionNeighbourhood, SingleDeletionNeighbourhood, SinglePerturbationNeighbourhood, SingleSwapNeighbourhood, SubsetNeighbourhood

public interface Neighbourhood<SolutionType extends Solution>

Interface of a neighbourhood that generates moves to transform a given solution into a neighbouring solution.

Author:

Herman De Beukelaer

Method Summary

Modifier and Type	Method and Description
List<? extends Move<? super SolutionType>>	getAllMoves(SolutionType solution) Get a list of all moves that can be applied to the given solution to transform it into each of the neighbouring solutions contained in this specific neighbourhood.
default Move<? super SolutionType>	getRandomMove(SolutionType solution) Generates a random move, using a default source of randomness.
Move<? super SolutionType>	getRandomMove(SolutionType solution, Random rnd) Generates a move that transforms the given solution into a random neighbour contained in this specific neighbourhood.

Method Detail

getRandomMove

Move<? super SolutionType> getRandomMove(SolutionType solution,
                                         Random rnd)

Generates a move that transforms the given solution into a random neighbour contained in this specific neighbourhood. If the neighbourhood does not contain any neighbours for the given solution, null is returned.

Parameters:

solution - solution to which the move is to be applied

rnd - source of randomness used to generate a random move

Returns:

random move transforming the given solution into a random neighbour, null if the given solution does not have any neighbours

getRandomMove

default Move<? super SolutionType> getRandomMove(SolutionType solution)

Generates a random move, using a default source of randomness. The default implementation delegates to getRandomMove(solution, ThreadLocalRandom.current()) where a thread local random generator is used to avoid overhead and contention for parallel calls.

Parameters:

solution - solution to which the move is to be applied

Returns:

random move transforming the given solution into a random neighbour, null if the given solution does not have any neighbours

getAllMoves

List<? extends Move<? super SolutionType>> getAllMoves(SolutionType solution)

Get a list of all moves that can be applied to the given solution to transform it into each of the neighbouring solutions contained in this specific neighbourhood. The returned list may be empty, in case the given solution does not have any neighbours.

Parameters:

solution - solution to which the moves are to be applied

Returns:

list of all moves for this neighbourhood, may be empty if the given solution does not have any neighbours