org.chocosolver.util.objects.graphs

Class DirectedGraph

java.lang.Object

org.chocosolver.util.objects.graphs.DirectedGraph

All Implemented Interfaces:

IGraph

public class DirectedGraph
extends Object
implements IGraph

Directed graph implementation : arcs are indexed per endpoints

Author:

Jean-Guillaume Fages, Xavier Lorca

Constructor Summary

Constructors

Constructor and Description
DirectedGraph(int n, SetType type, boolean allNodes) Creates an empty graph.
DirectedGraph(Model model, int n, SetType type, boolean allNodes) Creates an empty backtrable graph of n nodes Allocates memory for n nodes (but they should then be added explicitly, unless allNodes is true).

Method Summary

Modifier and Type	Method and Description
boolean	addArc(int from, int to) add arc (from,to) to the graph
boolean	addNode(int x) Adds node x to the node set of the graph
boolean	arcExists(int from, int to) Test whether arc (from,to) exists or not in the graph
int	getNbMaxNodes() The maximum number of nodes in the graph Vertices of the graph belong to [0,getNbMaxNodes()-1] This quantity is fixed at the creation of the graph
ISet	getNodes()
ISet	getPredOf(int x) Get predecessors of node x
ISet	getPredOrNeighOf(int x) Get either x's predecessors or neighbors.
ISet	getSuccOf(int x) Get successors of node x
ISet	getSuccOrNeighOf(int x) Get either x's successors or neighbors.
SetType	getType() Get the type of data structures used in the graph
boolean	isArcOrEdge(int from, int to) If this is directed returns true if and only if arc (x,y) exists Else, if this is undirected returns true if and only if edge (x,y) exists This method enables to capitalize some code but should be called with care
boolean	isDirected()
boolean	removeArc(int from, int to) remove arc (from,to) from the graph
boolean	removeNode(int x) Remove node x from the graph
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

DirectedGraph

public DirectedGraph(int n,
                     SetType type,
                     boolean allNodes)

Creates an empty graph. Allocates memory for n nodes (but they should then be added explicitly, unless allNodes is true).

Parameters:

n - maximum number of nodes

type - data structure to use for representing node successors and predecessors

allNodes - true iff all nodes must always remain present in the graph. i.e. The node set is fixed to [0,n-1] and will never change

DirectedGraph

public DirectedGraph(Model model,
                     int n,
                     SetType type,
                     boolean allNodes)

Creates an empty backtrable graph of n nodes Allocates memory for n nodes (but they should then be added explicitly, unless allNodes is true).

Parameters:

model - model providing the backtracking environment

n - maximum number of nodes

type - data structure to use for representing node successors and predecessors

allNodes - true iff all nodes must always remain present in the graph

Method Detail

toString

public String toString()

Overrides:

toString in class Object

getNbMaxNodes

public int getNbMaxNodes()

Description copied from interface: IGraph

The maximum number of nodes in the graph Vertices of the graph belong to [0,getNbMaxNodes()-1] This quantity is fixed at the creation of the graph

Specified by:

getNbMaxNodes in interface IGraph

Returns:

the maximum number of nodes of the graph

getNodes

public ISet getNodes()

Specified by:

getNodes in interface IGraph

Returns:

the collection of nodes present in the graph

getType

public SetType getType()

Description copied from interface: IGraph

Get the type of data structures used in the graph

Specified by:

getType in interface IGraph

Returns:

the type of data structures used in the graph

addNode

public boolean addNode(int x)

Description copied from interface: IGraph

Adds node x to the node set of the graph

Specified by:

addNode in interface IGraph

Parameters:

x - a node index

Returns:

true iff x was not already present in the graph

removeNode

public boolean removeNode(int x)

Description copied from interface: IGraph

Remove node x from the graph

Specified by:

removeNode in interface IGraph

Parameters:

x - a node index

Returns:

true iff x was present in the graph

removeArc

public boolean removeArc(int from,
                         int to)

remove arc (from,to) from the graph

Parameters:

from - a node index

to - a node index

Returns:

true iff arc (from,to) was in the graph

arcExists

public boolean arcExists(int from,
                         int to)

Test whether arc (from,to) exists or not in the graph

Parameters:

from - a node index

to - a node index

Returns:

true iff arc (from,to) exists in the graph

isArcOrEdge

public boolean isArcOrEdge(int from,
                           int to)

Description copied from interface: IGraph

If this is directed returns true if and only if arc (x,y) exists Else, if this is undirected returns true if and only if edge (x,y) exists

This method enables to capitalize some code but should be called with care

Specified by:

isArcOrEdge in interface IGraph

Parameters:

from - a node index

to - a node index

isDirected

public boolean isDirected()

Specified by:

isDirected in interface IGraph

Returns:

true if and only if this is a directed graph

addArc

public boolean addArc(int from,
                      int to)

add arc (from,to) to the graph

Parameters:

from - a node index

to - a node index

Returns:

true iff arc (from,to) was not already in the graph

getSuccOf

public ISet getSuccOf(int x)

Get successors of node x

Parameters:

x - node index

Returns:

successors of x

getSuccOrNeighOf

public ISet getSuccOrNeighOf(int x)

Description copied from interface: IGraph

Get either x's successors or neighbors.

This method enables to capitalize some code but should be called with care

Specified by:

getSuccOrNeighOf in interface IGraph

Parameters:

x - a node index

Returns:

x's successors if this is directed x's neighbors otherwise

getPredOf

public ISet getPredOf(int x)

Get predecessors of node x

Parameters:

x - node index

Returns:

predecessors of x

getPredOrNeighOf

public ISet getPredOrNeighOf(int x)

Description copied from interface: IGraph

Get either x's predecessors or neighbors.

This method enables to capitalize some code but should be called with care

Specified by:

getPredOrNeighOf in interface IGraph

Parameters:

x - a node index

Returns:

x's predecessors if this is directed x's neighbors otherwise