1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
|
/**
* This file is part of the CRISTAL-iSE kernel.
* Copyright (c) 2001-2014 The CRISTAL Consortium. All rights reserved.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 3 of the License, or (at
* your option) any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; with out even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* http://www.fsf.org/licensing/licenses/lgpl.html
*/
package com.c2kernel.graph.traversal;
import java.util.Vector;
import com.c2kernel.graph.model.GraphModel;
import com.c2kernel.graph.model.Vertex;
public class GraphTraversal
{
public static final int kUp = 1;
public static final int kDown = 2;
private GraphTraversal()
{
}
public static Vertex[] getTraversal(GraphModel graphModel, Vertex startVertex, int direction, boolean ignoreBackLinks)
{
Vector<Vertex> path = new Vector<Vertex>(10, 10);
graphModel.clearTags(startVertex);
visitVertex(startVertex, graphModel, path, direction, startVertex, ignoreBackLinks);
return vectorToVertexArray(path);
}
private static void visitVertex(Vertex vertex, GraphModel graphModel, Vector<Vertex> path, int direction, Object tag, boolean ignoreBackLinks)
{
Vertex[] children = null;
int i = 0;
if(direction == kDown)
{
children = graphModel.getOutVertices(vertex);
}
else
{
children = graphModel.getInVertices(vertex);
}
vertex.setTag(tag);
path.add(vertex);
for(i=0; i<children.length; i++)
{
if(!(children[i].hasTag(tag)))
{
boolean skipBackLink = false;
if ( ignoreBackLinks &&
((vertex.isJoin() && direction == kUp) ||
(vertex.isLoop() && direction == kDown))) {
Vertex[] following = getTraversal(graphModel, children[i], direction, false);
for (Vertex element : following) {
if (element == vertex) {
skipBackLink = true;
break;
}
}
}
if (!skipBackLink)
visitVertex(children[i], graphModel, path, direction, tag, ignoreBackLinks);
}
}
}
private static Vertex[] vectorToVertexArray(Vector<Vertex> vector)
{
Vertex[] vertices = new Vertex[vector.size()];
int i = 0;
for(i=0; i<vertices.length; i++)
{
vertices[i] = vector.elementAt(i);
}
return vertices;
}
}
|
