Package com.jgalgo.alg.shortestpath

Class NegativeCycleException

java.lang.Object

java.lang.Throwable

java.lang.Exception

java.lang.RuntimeException

com.jgalgo.alg.shortestpath.NegativeCycleException

All Implemented Interfaces:

Serializable

public class NegativeCycleException
extends RuntimeException

Exception thrown when a negative cycle is detected in a graph during a shortest path computation.

Negative weights are supported by some implementations of shortest path algorithm, and the 'shortest path' is well defined as long as there are no negative cycle in the graph as a path can loop in the cycle and achieve arbitrary small 'length'. When negative cycles exists, algorithms will raise NegativeCycleException exception.

Author:

Barak Ugav

See Also:

• ShortestPathSingleSource
• ShortestPathAllPairs
• Serialized Form

Constructor Summary

Constructors

Constructor	Description
NegativeCycleException(Graph<V,E> graph, Path<V,E> cycle)	Create a new instance of the exception.

Method Summary

Modifier and Type	Method	Description
Path<?,?>	cycle()	Get the negative cycle that was found in the graph.
<V, E> Path<V,E>	cycle(Graph<V,E> g)	Get the negative cycle that was found in the graph in type generic safe way.

Methods inherited from class java.lang.Throwable

addSuppressed, fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, getSuppressed, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

NegativeCycleException

public NegativeCycleException(Graph<V,E> graph,
 Path<V,E> cycle)

Create a new instance of the exception.

Type Parameters:

V - the vertices type

E - the edges type

Parameters:

graph - the graph on which the negative cycle was detected

cycle - the negative cycle that was found in the graph

Method Details

cycle

public Path<?,?> cycle()

Get the negative cycle that was found in the graph.

Returns:

the negative cycle that was found in the graph.

cycle

public <V,
E> Path<V,E> cycle(Graph<V,E> g)

Get the negative cycle that was found in the graph in type generic safe way.

by passing the graph on which the exception was thrown to this method, we can safely conclude the generic types of the return path and avoid unchecked casts.

Type Parameters:

V - the vertices type

E - the edges type

Parameters:

g - the graph on which the exception was thrown

Returns:

the negative cycle that was found in the graph.