State (S-Space Package 2.0.1 API)

All Known Implementing Classes:

TypedVF2State, VF2State
```
public interface State
```
An interface for representing the partial or complete state of an a attempted isomorphic mapping between two graphs. This interface exposes as set of common operations used by AbstractIsomorphismTester to detect isomorphism in a general manner while leaving the algorithm specifics isolated to a State implementation.

Field Summary

Fields
Modifier and Type Field and Description

static int NULL_NODE
The node marker to be used when indicating that that no node is being matched.

Fields
Modifier and Type	Field and Description
`static int`	`NULL_NODE` The node marker to be used when indicating that that no node is being matched.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addPair(int n1, int n2)` Adds the two vertices to this `State`'s vertex mapping.
`void`	`backTrack()` Undoes the mapping added in the prior call to `addPair`.
`State`	`copy()` Makes a shallow copy of the content of this state.
`Graph<? extends Edge>`	`getGraph1()` Returns the first graph being matched
`Graph<? extends Edge>`	`getGraph2()` Returns the first graph being matched
`Map<Integer,Integer>`	`getVertexMapping()` Returns the current mapping between vertices.
`boolean`	`isDead()` Returns `true` if the current state of mapping cannot proceed because some invalid mapping has occurred and no further pairs would result in an isomorphic match.
`boolean`	`isFeasiblePair(int node1, int node2)` Returns `true` if mapping `node1` to `node2` would preseve the isomorphism between the graphs to the extend that their vertices have been mapped thusfar.
`boolean`	`isGoal()` Returns `true` if all the vertices have been mapped.
`Pair<Integer>`	`nextPair(int prevN1, int prevN2)` Returns the next candidate for isomorphic matching given these prior two vertices that were matched.

- Field Detail
  - NULL_NODE
```
static final int NULL_NODE
```
    The node marker to be used when indicating that that no node is being matched.
    
    See Also:
    Constant Field Values
- Method Detail
  - getGraph1
```
Graph<? extends Edge> getGraph1()
```
    Returns the first graph being matched
  - getGraph2
```
Graph<? extends Edge> getGraph2()
```
    Returns the first graph being matched
  - nextPair
```
Pair<Integer> nextPair(int prevN1,
                     int prevN2)
```
    Returns the next candidate for isomorphic matching given these prior two vertices that were matched. If prevN1 and prevN1 are NULL_NODE, this should return the initial candidate.
  - addPair
```
void addPair(int n1,
           int n2)
```
    Adds the two vertices to this State's vertex mapping.
  - isFeasiblePair
```
boolean isFeasiblePair(int node1,
                     int node2)
```
    Returns true if mapping node1 to node2 would preseve the isomorphism between the graphs to the extend that their vertices have been mapped thusfar.
  - isGoal
```
boolean isGoal()
```
    Returns true if all the vertices have been mapped. Equivalently, returns true if the graphs are isomorphic.
  - isDead
```
boolean isDead()
```
    Returns true if the current state of mapping cannot proceed because some invalid mapping has occurred and no further pairs would result in an isomorphic match.
  - getVertexMapping
```
Map<Integer,Integer> getVertexMapping()
```
    Returns the current mapping between vertices.
  - copy
```
State copy()
```
    Makes a shallow copy of the content of this state.
  - backTrack
```
void backTrack()
```
    Undoes the mapping added in the prior call to addPair.

Interface State

Field Summary

Method Summary

Field Detail

NULL_NODE

Method Detail

getGraph1

getGraph2

nextPair

addPair

isFeasiblePair

isGoal

isDead

getVertexMapping

copy

backTrack