Module org.jhotdraw8.graph

Package org.jhotdraw8.graph.path.algo

Class UniqueArcPathSearchAlgo<V,A,C extends Number & Comparable<C>>

java.lang.Object

org.jhotdraw8.graph.path.algo.UniqueArcPathSearchAlgo<V,A,C>

Type Parameters:

V - the vertex data type

A - the arrow data type

C - the cost number type

All Implemented Interfaces:

ArcPathSearchAlgo<V,A,C>

public class UniqueArcPathSearchAlgo<V,A,C extends Number & Comparable<C>>
extends Object
implements ArcPathSearchAlgo<V,A,C>

Searches a globally unique vertex path from a set of start vertices to a set of goal vertices using a breadth-first search algorithm on a directed (potentially cyclic) graph (DIG).

Uniqueness is global up to (inclusive) the specified maximal depth.

This algorithm ignores cost limit. If you need it, use one of the shortest path search algorithms.

Performance characteristics:

When the algorithm returns a back link

exactly O( |A| + |V| ) within max depth

When the algorithm returns null

less or equal O( |A| + |V| ) within max depth

References:

Robert Sedgewick, Kevin Wayne. (2011)

Algorithms, 4th Edition. Chapter 4. Breadth-First Search. math.cmu.edu

Sampath Kannan, Sanjeef Khanna, Sudeepa Roy. (2008)

STCON in Directed Unique-Path Graphs. Chapter 2.1 Properties of Unique-Path Graphs. cis.upenn.edu

Constructor Summary

Constructors

Constructor	Description
UniqueArcPathSearchAlgo()

Method Summary

Modifier and Type	Method	Description
@Nullable ArcBackLinkWithAncestorSet<V,A>	search(@NonNull Iterable<V> startVertices, @NonNull Predicate<V> goalPredicate, @NonNull Function<V,Iterable<Arc<V,A>>> nextArcsFunction, int maxDepth)	Search engine method.
@Nullable ArcBackLinkWithCost<V,A,C>	search(@NonNull Iterable<V> startVertices, @NonNull Predicate<V> goalPredicate, @NonNull Function<V,Iterable<Arc<V,A>>> nextArcsFunction, int maxDepth, @NonNull C zero, @NonNull C costLimit, @NonNull Function3<V,V,A,C> costFunction, @NonNull BiFunction<C,C,C> sumFunction, @NonNull AddToSet<V> visited)	Search engine method.

Methods inherited from class java.lang.Object

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

Constructor Details

UniqueArcPathSearchAlgo

public UniqueArcPathSearchAlgo()

Method Details

search

public @Nullable ArcBackLinkWithCost<V,A,C> search(@NonNull Iterable<V> startVertices,
 @NonNull Predicate<V> goalPredicate,
 @NonNull Function<V,Iterable<Arc<V,A>>> nextArcsFunction,
 int maxDepth,
 @NonNull C zero,
 @NonNull C costLimit,
 @NonNull Function3<V,V,A,C> costFunction,
 @NonNull BiFunction<C,C,C> sumFunction,
 @NonNull AddToSet<V> visited)

Search engine method.

Specified by:

search in interface ArcPathSearchAlgo<V,A,C extends Number & Comparable<C>>

Parameters:

startVertices - the set of start vertices

goalPredicate - the goal predicate

nextArcsFunction - the next arcs function

maxDepth - the maximal depth (inclusive) of the search Must be >= 0.

zero - the zero cost value

costLimit - the cost limit is ignored

costFunction - the cost function

sumFunction - the sum function for adding two cost values

visited -

Returns:

search

public @Nullable ArcBackLinkWithAncestorSet<V,A> search(@NonNull Iterable<V> startVertices,
 @NonNull Predicate<V> goalPredicate,
 @NonNull Function<V,Iterable<Arc<V,A>>> nextArcsFunction,
 int maxDepth)

Search engine method.

Parameters:

startVertices - the set of start vertices

goalPredicate - the goal predicate

nextArcsFunction - the next arcs function

maxDepth - the maximal depth (inclusive) of the search Must be >= 0.

Returns:

on success: a back link, otherwise: null