ca.uqac.lif.ecp.graphs

Class Hypergraph

java.lang.Object

ca.uqac.lif.ecp.graphs.Hypergraph

public class Hypergraph
extends java.lang.Object

Implementation of an undirected hypergraph

Author:

Sylvain Hall�

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Hypergraph.Hyperedge

Field Summary

Fields

Modifier and Type	Field and Description
MathSet<Hypergraph.Hyperedge>	m_edges The set of hyperedges of the graph
protected int	m_vertexId A counter for vertex IDs for this graph
MathSet<java.lang.Integer>	m_vertices The set of vertices of the graph

Constructor Summary

Constructors

Constructor and Description
Hypergraph() Creates a new empty hypergraph

Method Summary

Modifier and Type	Method and Description
void	addEdge(Hypergraph.Hyperedge e) Adds a hyperedge to the hypergraph
int	getEdgeCount() Gets the number of hyperedges in the graph
int	getVertexCount() Gets the number of vertices in the graph
int	newVertex() Gets the ID of the next new vertex in this graph
static Hypergraph	parse(java.util.Scanner scanner) Creates a hypergraph from a stream of characters.
static Hypergraph	parse(java.lang.String s) Creates a hypergraph from a character string.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

m_edges

public MathSet<Hypergraph.Hyperedge> m_edges

The set of hyperedges of the graph

m_vertices

public MathSet<java.lang.Integer> m_vertices

The set of vertices of the graph

m_vertexId

protected int m_vertexId

A counter for vertex IDs for this graph

Constructor Detail

Hypergraph

public Hypergraph()

Creates a new empty hypergraph

Method Detail

addEdge

public void addEdge(Hypergraph.Hyperedge e)

Adds a hyperedge to the hypergraph

Parameters:

e - The hyperedge

newVertex

public int newVertex()

Gets the ID of the next new vertex in this graph

Returns:

The ID

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getEdgeCount

public int getEdgeCount()

Gets the number of hyperedges in the graph

Returns:

The number

getVertexCount

public int getVertexCount()

Gets the number of vertices in the graph

Returns:

The number

parse

public static Hypergraph parse(java.lang.String s)

Creates a hypergraph from a character string.

Parameters:

s - The string

Returns:

A hypergraph, or null if the graph could not be created

See Also:

parse(Scanner)

parse

public static Hypergraph parse(java.util.Scanner scanner)

Creates a hypergraph from a stream of characters. The character string should be formatted like this:

 # Empty lines and lines that start with '#' are ignored
 # The remaining lines should contain a comma-separated list of
 # vertex numbers (integers)
 0,1,2,3
 1,2,4
 2,3,6,1
 ...
 

Parameters:

s - The string, formatted as specified above

Returns:

A hypergraph, or null if the graph could not be created