Class PermutationInitializer
 java.lang.Object

 org.cicirello.search.operators.permutations.PermutationInitializer

 All Implemented Interfaces:
Splittable<Initializer<Permutation>>
,Initializer<Permutation>
public final class PermutationInitializer extends Object implements Initializer<Permutation>
The PermutationInitializer provides metaheuristic implementations, such as of simulated annealing, etc, with a way to generate random initial solutions to a problem, as well as a way to make copies of current solution configurations. Since it implements the
Initializer
interface, which relies on generics, such implementations of search algorithms such as simulated annealing, etc, do not need to know the representation of solutions.This initializer generates permutations uniformly at random from among the space of permutations. This is the typical case for many metaheuristics (e.g., hill climbers and simulated annealers often begin at a random solution).


Constructor Summary
Constructors Constructor Description PermutationInitializer(int n)
Constructs a PermutationInitializer.

Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description Permutation
createCandidateSolution()
Creates one candidate solution to a problem.PermutationInitializer
split()
Generates a functionally identical copy of this object, for use in multithreaded implementations of search algorithms.



Constructor Detail

PermutationInitializer
public PermutationInitializer(int n)
Constructs a PermutationInitializer. Parameters:
n
 The length of the permutations generated by this permutation initializer. n must be nonnegative. Throws:
IllegalArgumentException
 if n is negative.


Method Detail

createCandidateSolution
public Permutation createCandidateSolution()
Description copied from interface:Initializer
Creates one candidate solution to a problem. Specified by:
createCandidateSolution
in interfaceInitializer<Permutation>
 Returns:
 a candidate solution to a problem instance.

split
public PermutationInitializer split()
Description copied from interface:Splittable
Generates a functionally identical copy of this object, for use in multithreaded implementations of search algorithms. The state of the object that is returned may or may not be identical to that of the original. Thus, this is a distinct concept from the functionality of theCopyable
interface. Classes that implement this interface must ensure that the object returned performs the same functionality, and that it does not share any state data that would be either unsafe or inefficient for concurrent access by multiple threads. The split method is allowed to simply return the this reference, provided that it is both safe and efficient for multiple threads to share a single copy of the Splittable object. The intention is to provide a multithreaded search with the capability to provide spawned threads with their own distinct search operators. Such multithreaded algorithms can call the split method for each thread it spawns to generate a functionally identical copy of the operator, but with independent state. Specified by:
split
in interfaceSplittable<Initializer<Permutation>>
 Returns:
 A functionally identical copy of the object, or a reference to this if it is both safe and efficient for multiple threads to share a single instance of this Splittable object.

