java.lang.Object
- org.jgrapht.alg.isomorphism.VF2State<V,E>

Type Parameters:

V - the type of the vertices

E - the type of the edges

Direct Known Subclasses:

VF2GraphIsomorphismState, VF2SubgraphIsomorphismState
```
abstract class VF2State<V,E>
extends java.lang.Object
```
controls the matching between two graphs according to the VF2 algorithm.

Field Summary

Fields
Modifier and Type	Field	Description
`protected int`	`addedVertex1`
`protected int`	`addVertex1`
`protected int`	`addVertex2`
`protected int[]`	`core1`
`protected int[]`	`core2`
`protected int`	`coreLen`
`protected static boolean`	`DEBUG`
`protected java.util.Comparator<E>`	`edgeComparator`
`protected GraphOrdering<V,E>`	`g1`
`protected GraphOrdering<V,E>`	`g2`
`protected int[]`	`in1`
`protected int[]`	`in2`
`protected int`	`n1`
`protected int`	`n2`
`static int`	`NULL_NODE`
`protected int[]`	`out1`
`protected int[]`	`out2`
`protected int`	`t1BothLen`
`protected int`	`t1InLen`
`protected int`	`t1OutLen`
`protected int`	`t2BothLen`
`protected int`	`t2InLen`
`protected int`	`t2OutLen`
`protected java.util.Comparator<V>`	`vertexComparator`

Constructor Summary

Constructors
Constructor	Description
`VF2State(GraphOrdering<V,E> g1, GraphOrdering<V,E> g2, java.util.Comparator<V> vertexComparator, java.util.Comparator<E> edgeComparator)`
`VF2State(VF2State<V,E> s)`	copy constructor

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`addPair()`	adds the pair to the current matching.
`protected boolean`	`areCompatibleEdges(int v1, int v2, int u1, int u2)`	checks the edges from $v_1$ to $v_2$ and from $u_1$ to $u_2$ for semantic equivalence
`protected boolean`	`areCompatibleVertexes(int v1, int v2)`	checks the vertices $v_1$ and $v_2$ for semantic equivalence
`void`	`backtrack()`	removes the last added pair from the matching
`IsomorphicGraphMapping<V,E>`	`getCurrentMapping()`
`abstract boolean`	`isFeasiblePair()`
`boolean`	`isGoal()`
`boolean`	`nextPair()`	calculates a pair of nodes which may be added to the current matching, according to the VF2 algorithm.
`void`	`resetAddVertexes()`
`protected void`	`showLog(java.lang.String method, java.lang.String str)`	creates the debug output only if DEBUG is true.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NULL_NODE
```
public static final int NULL_NODE
```
See Also:

Constant Field Values

DEBUG
```
protected static final boolean DEBUG
```
See Also:

Constant Field Values

core1
```
protected final int[] core1
```

core2
```
protected final int[] core2
```

in1
```
protected final int[] in1
```

in2
```
protected final int[] in2
```

out1
```
protected final int[] out1
```

out2
```
protected final int[] out2
```

n1
```
protected final int n1
```

n2
```
protected final int n2
```

coreLen
```
protected int coreLen
```

t1BothLen
```
protected int t1BothLen
```

t2BothLen
```
protected int t2BothLen
```

t1InLen
```
protected int t1InLen
```

t2InLen
```
protected int t2InLen
```

t1OutLen
```
protected int t1OutLen
```

t2OutLen
```
protected int t2OutLen
```

addedVertex1
```
protected int addedVertex1
```

addVertex1
```
protected int addVertex1
```

addVertex2
```
protected int addVertex2
```

g1

protected final GraphOrdering<V,E> g1

g2

protected final GraphOrdering<V,E> g2

vertexComparator

protected final java.util.Comparator<V> vertexComparator

edgeComparator

protected final java.util.Comparator<E> edgeComparator

Constructor Detail
- VF2State
```
public VF2State(GraphOrdering<V,E> g1,
                GraphOrdering<V,E> g2,
                java.util.Comparator<V> vertexComparator,
                java.util.Comparator<E> edgeComparator)
```
  Parameters:
  
  g1 - GraphOrdering on first graph
  
  g2 - GraphOrdering on second graph (possible subgraph)
  
  vertexComparator - comparator for semantic equality of vertices
  
  edgeComparator - comparator for semantic equality of edges
- VF2State
```
public VF2State(VF2State<V,E> s)
```
  copy constructor
  
  Parameters:
  
  s -

Method Detail
- nextPair
```
public boolean nextPair()
```
  calculates a pair of nodes which may be added to the current matching, according to the VF2 algorithm.
  
  Returns:
  
  false, if there are no more pairs left
- addPair
```
public void addPair()
```
  adds the pair to the current matching.
- isGoal
```
public boolean isGoal()
```
  Returns:
  
  is the matching already complete?
- isFeasiblePair
```
public abstract boolean isFeasiblePair()
```
  Returns:
  
  true, if the already matched vertices of graph1 plus the first vertex of nextPair are isomorphic to the already matched vertices of graph2 and the second one vertex of nextPair.
- backtrack
```
public void backtrack()
```
  removes the last added pair from the matching
- areCompatibleVertexes
```
protected boolean areCompatibleVertexes(int v1,
                                        int v2)
```
  checks the vertices $v_1$ and $v_2$ for semantic equivalence
  
  Parameters:
  
  v1 -
  
  v2 -
  
  Returns:
  
  v1 and v2 are equivalent
- areCompatibleEdges
```
protected boolean areCompatibleEdges(int v1,
                                     int v2,
                                     int u1,
                                     int u2)
```
  checks the edges from $v_1$ to $v_2$ and from $u_1$ to $u_2$ for semantic equivalence
  
  Parameters:
  
  v1 -
  
  v2 -
  
  u1 -
  
  u2 -
  
  Returns:
  
  edges are equivalent
- getCurrentMapping
```
public IsomorphicGraphMapping<V,E> getCurrentMapping()
```
- resetAddVertexes
```
public void resetAddVertexes()
```
- showLog
```
protected void showLog(java.lang.String method,
                       java.lang.String str)
```
  creates the debug output only if DEBUG is true.
  
  Parameters:
  
  method -
  
  str -

Class VF2State<V,​E>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

NULL_NODE

DEBUG

core1

core2

in1

in2

out1

out2

n1

n2

coreLen

t1BothLen

t2BothLen

t1InLen

t2InLen

t1OutLen

t2OutLen

addedVertex1

addVertex1

addVertex2

g1

g2

vertexComparator

edgeComparator

Constructor Detail

VF2State

VF2State

Method Detail

nextPair

addPair

isGoal

isFeasiblePair

backtrack

areCompatibleVertexes

areCompatibleEdges

getCurrentMapping

resetAddVertexes

showLog

Class VF2State<V,E>