+++ /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 for representing subgraphs of any graph.
-* The subgraph is defined the following way.
-* The subgraph always contains all the nodes of the original underlying
-* graph. However, it is possible to remove edges by flagging nodes as
-* removed, in which case
-* the edges that have at least one end on those nodes are removed.
-* If the underlying graph changes after initialization, this class follows
-* the change.
-*/
-public class SubGraphEdges implements Graph {
-
-
-// ====================== private fields ========================
-// ==============================================================
-
-
-private final Graph g;
-
-private final BitSet nodes;
-
-
-// ====================== public constructors ===================
-// ==============================================================
-
-
-/**
-* Constructs an initially empty subgraph of g. That is, the subgraph will
-* contain no nodes.
-*/
-public SubGraphEdges( Graph g ) {
-
- this.g = g;
- nodes = new BitSet(g.size());
-}
-
-
-// ======================= Graph implementations ================
-// ==============================================================
-
-
-public boolean isEdge(int i, int j) {
-
- return nodes.get(i) && nodes.get(j) && g.isEdge(i,j);
-}
-
-// ---------------------------------------------------------------
-
-public Collection<Integer> getNeighbours(int i) {
-
- List<Integer> result = new LinkedList<Integer>();
- if( nodes.get(i) )
- {
- for(Integer in:g.getNeighbours(i))
- {
- if( nodes.get(in) ) result.add(in);
- }
- }
-
- return Collections.unmodifiableCollection(result);
-}
-
-// ---------------------------------------------------------------
-
-public Object getNode(int i) { return g.getNode(i); }
-
-// ---------------------------------------------------------------
-
-/**
-* If both i and j are within the node set of the subgraph and the original
-* graph has an (i,j) edge, returns that edge.
-*/
-public Object getEdge(int i, int j) {
-
- if( isEdge(i,j) ) return g.getEdge(i,j);
- return null;
-}
-
-// --------------------------------------------------------------------
-
-public int size() { return g.size(); }
-
-// --------------------------------------------------------------------
-
-public boolean directed() { return g.directed(); }
-
-// --------------------------------------------------------------------
-
-/** 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) {
-
- int degree=0;
- if( nodes.get(i) )
- {
- for(Integer in:g.getNeighbours(i))
- {
- if( nodes.get(in) ) degree++;
- }
- }
- return degree;
-}
-
-
-// ================= public functions =================================
-// ====================================================================
-
-
-/**
-* This function returns the size of the subgraph, i.e. the number of nodes
-* in the subgraph.
-*/
-public int subGraphSize() { return nodes.cardinality(); }
-
-// --------------------------------------------------------------------
-
-/**
-* Removes given node from subgraph.
-* @return true if the node was already in the subgraph otherwise false.
-*/
-public boolean removeNode(int i) {
-
- boolean was = nodes.get(i);
- nodes.clear(i);
- return was;
-}
-
-// --------------------------------------------------------------------
-
-/**
-* Adds given node to subgraph.
-* @return true if the node was already in the subgraph otherwise false.
-*/
-public boolean addNode(int i) {
-
- boolean was = nodes.get(i);
- nodes.set(i);
- return was;
-}
-}
-
