com.codemelon.graph.edge

Enum EdgeType

java.lang.Object

java.lang.Enum<EdgeType>

com.codemelon.graph.edge.EdgeType

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<EdgeType>

public enum EdgeType
extends java.lang.Enum<EdgeType>

Enumeration of different edge types, as are determined in depth-first search. Cf. CLRS, p. 609

Enum Constant Summary

Enum Constants

Enum Constant and Description
BACK Those edges (u, v) connecting a vertex u to an ancestor v in a depth-first tree.
CROSS All other edges.
FORWARD Those nontree edges (u, v) connecting a vertex u to a descendant v in a depth-first tree.
TREE Edges in a depth-first forest.
UNKNOWN Default edge type

Method Summary

Methods

Modifier and Type	Method and Description
static EdgeType	valueOf(java.lang.String name) Returns the enum constant of this type with the specified name.
static EdgeType[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

UNKNOWN

public static final EdgeType UNKNOWN

Default edge type

TREE

public static final EdgeType TREE

Edges in a depth-first forest. Edge (u, v) is a tree edge if v was first diescovered by exploring edge (u, v)

BACK

public static final EdgeType BACK

Those edges (u, v) connecting a vertex u to an ancestor v in a depth-first tree. We consider self-loops, which may occur in directed graphs, to be back edges.

FORWARD

public static final EdgeType FORWARD

Those nontree edges (u, v) connecting a vertex u to a descendant v in a depth-first tree.

CROSS

public static final EdgeType CROSS

All other edges. They can go between vertices in the same depth-first tree, as long as one vertex is not an ancestor of the other, or they can go between vertices in different depth-first trees.

Method Detail

values

public static EdgeType[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (EdgeType c : EdgeType.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static EdgeType valueOf(java.lang.String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

java.lang.IllegalArgumentException - if this enum type has no constant with the specified name

java.lang.NullPointerException - if the argument is null