+++ /dev/null
-/*
- * Copyright (c) 2003-2005 The BISON Project
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Lesser General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without 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 program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- */
-
-package peersim.graph;
-
-import java.util.*;
-
-/**
-* This class is an adaptor making any Graph an undirected graph
-* by making its edges bidirectional. The graph to be made undirected
-* is passed to the constructor. Only the reference is stored so
-* if the directed graph changes later, the undirected version will
-* follow that change. However, {@link #getNeighbours} has O(n) time complexity
-* (in other words, too slow for large graphs).
-* @see ConstUndirGraph
-*/
-public class UndirectedGraph implements Graph {
-
-
-// ====================== private fileds ========================
-// ==============================================================
-
-
-private final Graph g;
-
-
-// ====================== public constructors ===================
-// ==============================================================
-
-
-public UndirectedGraph( Graph g ) {
-
- this.g = g;
-}
-
-
-// ======================= Graph implementations ================
-// ==============================================================
-
-
-public boolean isEdge(int i, int j) {
-
- return g.isEdge(i,j) || g.isEdge(j,i);
-}
-
-// ---------------------------------------------------------------
-
-/**
-* Uses sets as collection so does not support multiple edges now, even if
-* the underlying directed graph does.
-*/
-public Collection<Integer> getNeighbours(int i) {
-
- Set<Integer> result = new HashSet<Integer>();
- result.addAll(g.getNeighbours(i));
- final int max = g.size();
- for(int j=0; j<max; ++j)
- {
- if( g.isEdge(j,i) ) result.add(j);
- }
-
- return Collections.unmodifiableCollection(result);
-}
-
-// ---------------------------------------------------------------
-
-public Object getNode(int i) { return g.getNode(i); }
-
-// ---------------------------------------------------------------
-
-/**
-* If there is an (i,j) edge, returns that, otherwise if there is a (j,i)
-* edge, returns that, otherwise returns null.
-*/
-public Object getEdge(int i, int j) {
-
- if( g.isEdge(i,j) ) return g.getEdge(i,j);
- if( g.isEdge(j,i) ) return g.getEdge(j,i);
- return null;
-}
-
-// ---------------------------------------------------------------
-
-public int size() { return g.size(); }
-
-// --------------------------------------------------------------------
-
-public boolean directed() { return false; }
-
-// --------------------------------------------------------------------
-
-/** not supported */
-public boolean setEdge( int i, int j ) {
-
- throw new UnsupportedOperationException();
-}
-
-// ---------------------------------------------------------------
-
-/** not supported */
-public boolean clearEdge( int i, int j ) {
-
- throw new UnsupportedOperationException();
-}
-
-// --------------------------------------------------------------------
-
-public int degree(int i) {
-
- return getNeighbours(i).size();
-}
-
-// --------------------------------------------------------------------
-/*
-public static void main( String[] args ) {
-
-
- Graph net = null;
- UndirectedGraph ug = new UndirectedGraph(net);
- for(int i=0; i<net.size(); ++i)
- System.err.println(i+" "+net.getNeighbours(i));
- System.err.println("============");
- for(int i=0; i<ug.size(); ++i)
- System.err.println(i+" "+ug.getNeighbours(i));
- for(int i=0; i<ug.size(); ++i)
- {
- for(int j=0; j<ug.size(); ++j)
- System.err.print(ug.isEdge(i,j)?"W ":"- ");
- System.err.println();
- }
-
- GraphIO.writeGML(net,System.out);
-}
-*/
-}
-
-
