Package org.ddolib.ddo.core.mdd

Class NodeSubProblemComparator<T>

java.lang.Object

org.ddolib.ddo.core.mdd.NodeSubProblemComparator<T>

Type Parameters:

T - the type of state contained in the subproblems

All Implemented Interfaces:

Comparator<NodeSubProblem<T>>

public final class NodeSubProblemComparator<T>
extends Object
implements Comparator<NodeSubProblem<T>>

Comparator for NodeSubProblem instances that sorts them first by their node value, and then by the state using a provided StateRanking if the values are equal.

This class implements a decorator pattern, allowing a StateRanking to be used as a tie-breaker when node values are identical. It is useful for prioritizing subproblems in search or decision diagram algorithms.

Constructor Summary

Constructors

Constructor	Description
NodeSubProblemComparator(StateRanking<T> delegate)	Constructs a new comparator that uses the given ranking as a tie-breaker.

Method Summary

Modifier and Type	Method	Description
int	compare(NodeSubProblem<T> o1, NodeSubProblem<T> o2)	Compares two NodeSubProblem instances.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

equals, reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Constructor Details

NodeSubProblemComparator

public NodeSubProblemComparator(StateRanking<T> delegate)

Constructs a new comparator that uses the given ranking as a tie-breaker.

Parameters:

delegate - the StateRanking used to compare states when node values are equal

Method Details

compare

public int compare(NodeSubProblem<T> o1,
 NodeSubProblem<T> o2)

Compares two NodeSubProblem instances.

First, compares by the node value. If the values are equal, the comparison is delegated to the StateRanking in reversed order.

Specified by:

compare in interface Comparator<T>

Parameters:

o1 - the first subproblem to compare

o2 - the second subproblem to compare

Returns:

a negative integer, zero, or a positive integer as the first subproblem is less than, equal to, or greater than the second