|
|||||||||
| PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
| SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD | ||||||||
java.lang.Objectorg._3pq.jgrapht.traverse.AbstractGraphIterator
org._3pq.jgrapht.traverse.CrossComponentIterator
org._3pq.jgrapht.traverse.TopologicalOrderIterator
public class TopologicalOrderIterator
Implements topological order traversal for a directed graph. A topological sort is a permutation p of the vertices of a graph such that an edge (i,j) implies that i appears before j in p (Skiena 1990, p. 208). See also http://mathworld.wolfram.com/TopologicalSort.html.
See "Algorithms in Java, Third Edition, Part 5: Graph Algorithms" by Robert Sedgewick and "Data Structures and Algorithms with Object-Oriented Design Patterns in Java" by Bruno R. Preiss for implementation alternatives. The latter can be found online at http://www.brpreiss.com/books/opus5/
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.
| Constructor Summary | |
|---|---|
TopologicalOrderIterator(DirectedGraph dg)
Creates a new topological order iterator over the directed graph specified. |
|
| Method Summary | |
|---|---|
protected void |
encounterVertex(java.lang.Object vertex,
Edge edge)
Update data structures the first time we see a vertex. |
protected void |
encounterVertexAgain(java.lang.Object vertex,
Edge edge)
Called whenever we re-encounter a vertex. |
protected boolean |
isConnectedComponentExhausted()
Returns true if there are no more uniterated vertices in the currently iterated connected component; false otherwise. |
protected java.lang.Object |
provideNextVertex()
Returns the vertex to be returned in the following call to the iterator next method. |
| Methods inherited from class org._3pq.jgrapht.traverse.CrossComponentIterator |
|---|
getSeenData, hasNext, isSeenVertex, next, putSeenData |
| Methods inherited from class org._3pq.jgrapht.traverse.AbstractGraphIterator |
|---|
addTraversalListener, fireConnectedComponentFinished, fireConnectedComponentStarted, fireEdgeTraversed, fireVertexTraversed, isCrossComponentTraversal, isReuseEvents, remove, removeTraversalListener, setCrossComponentTraversal, setReuseEvents |
| Methods inherited from class java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Constructor Detail |
|---|
public TopologicalOrderIterator(DirectedGraph dg)
dg - the directed graph to be iterated.| Method Detail |
|---|
protected boolean isConnectedComponentExhausted()
CrossComponentIterator
isConnectedComponentExhausted in class CrossComponentIteratorCrossComponentIterator.isConnectedComponentExhausted()
protected void encounterVertex(java.lang.Object vertex,
Edge edge)
CrossComponentIterator
encounterVertex in class CrossComponentIteratorvertex - the vertex encounterededge - the edge via which the vertex was encountered, or null if
the vertex is a starting pointCrossComponentIterator.encounterVertex(Object, Edge)
protected void encounterVertexAgain(java.lang.Object vertex,
Edge edge)
CrossComponentIterator
encounterVertexAgain in class CrossComponentIteratorvertex - the vertex re-encounterededge - the edge via which the vertex was re-encounteredCrossComponentIterator.encounterVertexAgain(Object, Edge)protected java.lang.Object provideNextVertex()
CrossComponentIteratornext method.
provideNextVertex in class CrossComponentIteratorCrossComponentIterator.provideNextVertex()
|
|||||||||
| PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
| SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD | ||||||||