- Type Parameters:
V
- the graph vertex typeE
- the graph edge type
For this iterator to work correctly the graph must not be modified during iteration. Currently there are no means to ensure that, nor to fail-fast. The results of such modifications are undefined.
The main idea of this algorithm is to divide each path between the source
and the
sink
into the root part - the part that coincides within some of the paths computed so
far, and the spur part, the part that deviates from all other paths computed so far. Therefore,
for each path the algorithm maintains a vertex, at which the path deviates from its "parent" path
(the candidate path using which it was computed).
First the algorithm finds the shortest path between the source
and the sink
,
which is put into the candidates heap. The source
is assigned to be its deviation vertex.
Then on each iteration the algorithm takes a candidate from the heap with minimum weight, puts it
into the result list and builds all possible deviations from it wrt. other paths, that are in the
result list. By generating spur paths starting only from the vertices that are after the
deviation vertex of current path (including the deviation vertex) it is possible to avoid
building duplicated candidates.
Additionally, the algorithm supports path validation by means of PathValidator
.
- Author:
- Semen Chudakov
- See Also:
-
Constructor Summary
ConstructorDescriptionConstructs an instance of the algorithm for givengraph
,source
andsink
.YenShortestPathIterator
(Graph<V, E> graph, V source, V sink, Supplier<org.jheaps.AddressableHeap<Double, Pair<GraphPath<V, E>, Boolean>>> heapSupplier) Constructs an instance of the algorithm for givengraph
,source
,sink
andheapSupplier
.YenShortestPathIterator
(Graph<V, E> graph, V source, V sink, Supplier<org.jheaps.AddressableHeap<Double, Pair<GraphPath<V, E>, Boolean>>> heapSupplier, PathValidator<V, E> pathValidator) Constructs an instance of the algorithm for givengraph
,source
,sink
,heapSupplier
andpathValidator
.YenShortestPathIterator
(Graph<V, E> graph, V source, V sink, PathValidator<V, E> pathValidator) Constructs an instance of the algorithm for givengraph
,source
,sink
andpathValidator
. -
Method Summary
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface java.util.Iterator
forEachRemaining, remove
-
Constructor Details
-
YenShortestPathIterator
Constructs an instance of the algorithm for givengraph
,source
andsink
.- Parameters:
graph
- graphsource
- source vertexsink
- sink vertex
-
YenShortestPathIterator
public YenShortestPathIterator(Graph<V, E> graph, V source, V sink, PathValidator<V, E> pathValidator) Constructs an instance of the algorithm for givengraph
,source
,sink
andpathValidator
. ThepathValidator
can benull
, which will indicate that all paths are valid.- Parameters:
graph
- graphsource
- source vertexsink
- sink vertexpathValidator
- validator to computed paths
-
YenShortestPathIterator
public YenShortestPathIterator(Graph<V, E> graph, V source, V sink, Supplier<org.jheaps.AddressableHeap<Double, Pair<GraphPath<V, E>, Boolean>>> heapSupplier) Constructs an instance of the algorithm for givengraph
,source
,sink
andheapSupplier
.- Parameters:
graph
- graphsource
- source vertexsink
- sink vertexheapSupplier
- supplier of the preferable heap implementation
-
YenShortestPathIterator
public YenShortestPathIterator(Graph<V, E> graph, V source, V sink, Supplier<org.jheaps.AddressableHeap<Double, Pair<GraphPath<V, E>, Boolean>>> heapSupplier, PathValidator<V, E> pathValidator) Constructs an instance of the algorithm for givengraph
,source
,sink
,heapSupplier
andpathValidator
. ThepathValidator
can benull
, which will indicate that all paths are valid.- Parameters:
graph
- graphsource
- source vertexsink
- sink vertexheapSupplier
- supplier of the preferable heap implementationpathValidator
- validator for computed paths
-
-
Method Details