+++ /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.Collection;
-
-/**
-* A general graph interface. It follows the following model:
-* the graph has n nodes which are indexed from 0 to n-1.
-* The parameters of operators refer to indices only.
-* Implementations might return objects that represent the
-* nodes or edges, although this is not required.
-*
-* Undirected graphs are modelled by the interface as directed graphs in which
-* every edge (i,j) has a corresponding reverse edge (j,i).
-*/
-public interface Graph {
-
- /**
- * Returns true if there is a directed edge between node i
- * and node j.
- */
- boolean isEdge(int i, int j);
-
- /**
- * Returns a collection view to all outgoing edges from
- * i. The collection should ideally be unmodifiable.
- * In any case, modifying the returned collection is not safe and
- * may result in unspecified behavior.
- */
- Collection<Integer> getNeighbours(int i);
-
- /**
- * Returns the node object associated with the index. Optional
- * operation.
- */
- Object getNode(int i);
-
- /**
- * Returns the edge object associated with the index. Optional
- * operation.
- */
- Object getEdge(int i, int j);
-
- /**
- * The number of nodes in the graph.
- */
- int size();
-
- /**
- * Returns true if the graph is directed otherwise false.
- */
- boolean directed();
-
- /**
- * Sets given edge, returns true if it did not exist before.
- * If the graph is
- * undirected, sets the edge (j,i) as well. Optional operation.
- */
- public boolean setEdge(int i, int j);
-
- /**
- * Removes given edge, returns true if it existed before. If the graph is
- * undirected, removes the edge (j,i) as well. Optional operation.
- */
- public boolean clearEdge(int i, int j);
-
- /**
- * Returns the degree of the given node. If the graph is directed,
- * returns out degree.
- */
- public int degree(int i);
-}
