org.jgrapht.graph.DirectedGraphUnion Maven / Gradle / Ivy

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/*
 * (C) Copyright 2009-2016, by Ilya Razenshteyn and Contributors.
 *
 * JGraphT : a free Java graph-theory library
 *
 * This program and the accompanying materials are dual-licensed under
 * either
 *
 * (a) the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation, or (at your option) any
 * later version.
 *
 * or (per the licensee's choosing)
 *
 * (b) the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation.
 */
package org.jgrapht.graph;

import java.util.*;

import org.jgrapht.*;
import org.jgrapht.util.*;

/**
 * A union of directed graphs.
 * 
 * @param  the graph vertex type
 * @param  the graph edge type
 */
public class DirectedGraphUnion
    extends GraphUnion>
    implements DirectedGraph
{
    private static final long serialVersionUID = -740199233080172450L;

    /**
     * Construct a new directed graph union.
     * 
     * @param g1 the first graph
     * @param g2 the second graph
     * @param operator the weight combiner (policy for edge weight calculation)
     */
    public DirectedGraphUnion(
        DirectedGraph g1, DirectedGraph g2, WeightCombiner operator)
    {
        super(g1, g2, operator);
    }

    /**
     * Construct a new directed graph union. The union will use the {@link WeightCombiner#SUM}
     * weight combiner.
     * 
     * @param g1 the first graph
     * @param g2 the second graph
     */
    public DirectedGraphUnion(DirectedGraph g1, DirectedGraph g2)
    {
        super(g1, g2);
    }

    @Override
    public int inDegreeOf(V vertex)
    {
        Set res = incomingEdgesOf(vertex);
        return res.size();
    }

    @Override
    public Set incomingEdgesOf(V vertex)
    {
        Set res = new HashSet<>();
        if (getG1().containsVertex(vertex)) {
            res.addAll(getG1().incomingEdgesOf(vertex));
        }
        if (getG2().containsVertex(vertex)) {
            res.addAll(getG2().incomingEdgesOf(vertex));
        }
        return Collections.unmodifiableSet(res);
    }

    @Override
    public int outDegreeOf(V vertex)
    {
        Set res = outgoingEdgesOf(vertex);
        return res.size();
    }

    @Override
    public Set outgoingEdgesOf(V vertex)
    {
        Set res = new HashSet<>();
        if (getG1().containsVertex(vertex)) {
            res.addAll(getG1().outgoingEdgesOf(vertex));
        }
        if (getG2().containsVertex(vertex)) {
            res.addAll(getG2().outgoingEdgesOf(vertex));
        }
        return Collections.unmodifiableSet(res);
    }
}

// End DirectedGraphUnion.java