org.jgrapht.alg.util

Class VertexDegreeComparator<V,E>

java.lang.Object

org.jgrapht.alg.util.VertexDegreeComparator<V,E>

Type Parameters:

V - the graph vertex type

E - the graph edge type

All Implemented Interfaces:

java.util.Comparator<V>

public class VertexDegreeComparator<V,E>
extends java.lang.Object
implements java.util.Comparator<V>

Compares two vertices based on their degree.

Used by greedy algorithms that need to sort vertices by their degree. Two vertices are considered equal if their degrees are equal.

Since:

Nov 6, 2003

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	VertexDegreeComparator.Order Order in which we sort the vertices: ascending vertex degree or descending vertex degree

Constructor Summary

Constructors

Constructor and Description
VertexDegreeComparator(UndirectedGraph<V,E> g) Creates a comparator for comparing the degrees of vertices in the specified graph.
VertexDegreeComparator(UndirectedGraph<V,E> g, VertexDegreeComparator.Order order) Creates a comparator for comparing the degrees of vertices in the specified graph.

Method Summary

Modifier and Type	Method and Description
int	compare(V v1, V v2) Compare the degrees of v1 and v2, taking into account whether ascending or descending order is used.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Comparator

comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Constructor Detail

VertexDegreeComparator

public VertexDegreeComparator(UndirectedGraph<V,E> g)

Creates a comparator for comparing the degrees of vertices in the specified graph. The comparator compares in ascending order of degrees (lowest first).

Parameters:

g - graph with respect to which the degree is calculated.

VertexDegreeComparator

public VertexDegreeComparator(UndirectedGraph<V,E> g,
                              VertexDegreeComparator.Order order)

Creates a comparator for comparing the degrees of vertices in the specified graph.

Parameters:

g - graph with respect to which the degree is calculated.

order - order in which the vertices are sorted (ascending or descending)

Method Detail

compare

public int compare(V v1,
                   V v2)

Compare the degrees of v1 and v2, taking into account whether ascending or descending order is used.

Specified by:

compare in interface java.util.Comparator<V>

Parameters:

v1 - the first vertex to be compared.

v2 - the second vertex to be compared.

Returns:

-1 if v1 comes before v2, +1 if v1 comes after v2, 0 if equal.