org.jamesframework.ext.permutation.neigh.moves

Class ReverseSubsequenceMove

java.lang.Object

org.jamesframework.ext.permutation.neigh.moves.ReverseSubsequenceMove

All Implemented Interfaces:

org.jamesframework.core.search.neigh.Move<PermutationSolution>

public class ReverseSubsequenceMove
extends Object
implements org.jamesframework.core.search.neigh.Move<PermutationSolution>

A move that reverses a subsequence of a permutation.

Author:

Herman De Beukelaer

Constructor Summary

Constructors

Constructor and Description
ReverseSubsequenceMove(int from, int to) Create a move that will reverse the subsequence from one up to another position in the permutation.

Method Summary

Modifier and Type	Method and Description
void	apply(PermutationSolution solution) Reverse the subsequence by performing a series of swaps in the given permutation solution.
boolean	equals(Object obj) Two moves of this type are considered equals if they reverse the same subsequence.
int	getFrom() Get the first position in the reversed subsequence.
int	getTo() Get the last position in the reversed subsequence.
int	hashCode() Hash code computation corresponding to implementation of equals(Object).
void	undo(PermutationSolution solution) Undo move by reverting the order of the reversed subsequence.

Methods inherited from class java.lang.Object

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

Constructor Detail

ReverseSubsequenceMove

public ReverseSubsequenceMove(int from,
                              int to)

Create a move that will reverse the subsequence from one up to another position in the permutation. It is allowed that from is larger than to as the first item is cyclically defined as the successor of the last item. Yet, both positions should be different.

Parameters:

from - first position of reversed subsequence

to - last position of reversed subsequence

Throws:

IllegalArgumentException - if from and to are equal

Method Detail

getFrom

public int getFrom()

Get the first position in the reversed subsequence.

Returns:

initial position in the reversed subsequence

getTo

public int getTo()

Get the last position in the reversed subsequence.

Returns:

final position in the reversed subsequence

apply

public void apply(PermutationSolution solution)

Reverse the subsequence by performing a series of swaps in the given permutation solution.

Specified by:

apply in interface org.jamesframework.core.search.neigh.Move<PermutationSolution>

Parameters:

solution - permutation solution to which the move is to be applied

undo

public void undo(PermutationSolution solution)

Undo move by reverting the order of the reversed subsequence.

Specified by:

undo in interface org.jamesframework.core.search.neigh.Move<PermutationSolution>

Parameters:

solution - permutation solution to which the move had been applied

equals

public boolean equals(Object obj)

Two moves of this type are considered equals if they reverse the same subsequence.

Overrides:

equals in class Object

Parameters:

obj - object to compare for equality

Returns:

true if the other object is a move of the same type that reverses the same subsequence

hashCode

public int hashCode()

Hash code computation corresponding to implementation of equals(Object).

Overrides:

hashCode in class Object

Returns:

hash code