DegeneracyOrderingIterator (JGraphT : a free Java graph library)

java.lang.Object
- org.jgrapht.traverse.AbstractGraphIterator<V,E>
- - org.jgrapht.traverse.DegeneracyOrderingIterator<V,E>

Type Parameters:

V - the graph vertex type

E - the graph edge type

All Implemented Interfaces:

java.util.Iterator<V>, GraphIterator<V,E>
```
public class DegeneracyOrderingIterator<V,E>
extends AbstractGraphIterator<V,E>
```
A degeneracy ordering iterator.
The degeneracy of a graph $G $is the smallest value d such that every nonempty subgraph of $G$ contains a vertex of degree at most $d.$ If a graph has degeneracy $d$, then it has a degeneracy ordering, an ordering such that each vertex has $d$ or fewer neighbors that come later in the ordering.
The iterator crosses components but does not track them, it only tracks visited vertices.
The iterator treats the input graph as undirected even if the graph is directed. Moreover, it completely ignores self-loops, meaning that it operates as if self-loops do not contribute to the degree of a vertex.

Author:

Dimitrios Michail

Field Summary
- Fields inherited from class org.jgrapht.traverse.AbstractGraphIterator
  crossComponentTraversal, graph, nListeners, reusableEdgeEvent, reusableVertexEvent, reuseEvents

Constructor Summary

Constructors
Constructor Description

DegeneracyOrderingIterator(Graph<V,E> graph)
Constructor

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`hasNext()`
`boolean`	`isCrossComponentTraversal()`	Test whether this iterator is set to traverse the graph across connected components.
`V`	`next()`
`void`	`setCrossComponentTraversal(boolean crossComponentTraversal)`	Sets the cross component traversal flag - indicates whether to traverse the graph across connected components.

Methods inherited from class org.jgrapht.traverse.AbstractGraphIterator
addTraversalListener, createEdgeTraversalEvent, createVertexTraversalEvent, fireConnectedComponentFinished, fireConnectedComponentStarted, fireEdgeTraversed, fireVertexFinished, fireVertexTraversed, getGraph, isReuseEvents, remove, removeTraversalListener, setReuseEvents

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

- Constructor Detail
  - DegeneracyOrderingIterator
```
public DegeneracyOrderingIterator(Graph<V,E> graph)
```
    Constructor
    
    Parameters:
    
    graph - the graph to be iterated
- Method Detail
  - isCrossComponentTraversal
```
public boolean isCrossComponentTraversal()
```
    Test whether this iterator is set to traverse the graph across connected components. Always returns true since the iterator does not care about components.
    
    Specified by:
    
    isCrossComponentTraversal in interface GraphIterator<V,E>
    
    Overrides:
    
    isCrossComponentTraversal in class AbstractGraphIterator<V,E>
    
    Returns:
    
    true if traverses across connected components, otherwise false.
  - setCrossComponentTraversal
```
public void setCrossComponentTraversal(boolean crossComponentTraversal)
```
    Sets the cross component traversal flag - indicates whether to traverse the graph across connected components. Trying to disable the cross components nature of this iterator will result into throwing a IllegalArgumentException.
    
    Overrides:
    
    setCrossComponentTraversal in class AbstractGraphIterator<V,E>
    
    Parameters:
    
    crossComponentTraversal - if true traverses across connected components.
  - hasNext
```
public boolean hasNext()
```
  - next
```
public V next()
```