package MaxFlowApplet.graph;

import java.util.Vector;

public class Vertex    {
    // returns the number of outgoing edges
    public int fanOut()
    {
        return edgeOut.size();
    };
    // returns the number of incoming edges
    public int fanIn()
    {
        return edgeIn.size();
    };
    // returns the index-th outgoing edge (from 0)
    public Edge getEdgeOut(int index)
    {
        return (Edge) edgeOut.elementAt(index);
    };
    // returns the index-th incoming edge (from 0)
    public Edge getEdgeIn(int index)
    {
        return (Edge) edgeIn.elementAt(index);
    };
    // true iff there is an edge to vertex v
    public boolean isNeighbour(Vertex v)
    {
        return getEdgeTo(v)!=null;
    };
    // returns the edge to vertex v
    public Edge getEdgeTo(Vertex v)
    {
        Edge e;
        int n = fanOut();
        for(int i = 0; i < n; i++)
        {
            e = getEdgeOut(i);
            if (e.getVertexTo() == v)
                return e;
        };
        return null;
    };
    // adds an incoming edge
    public void addEdgeIn(Edge e)
    {
        edgeIn.addElement(e);
    };
    // adds an outgoing edge
    public void addEdgeOut(Edge e)
    {
        edgeOut.addElement(e);
    };
    // removes an outgoing edge
    public void removeEdgeOut(Edge e)
    {
        edgeOut.removeElement(e);
    };
    // removes an incoming edge
    public void removeEdgeIn(Edge e)
    {
        edgeIn.removeElement(e);
    };

    // vector of incoming edges
    protected Vector edgeIn = new Vector(INITIALSIZE, CAPINCREMENT);
    // vector of outgoing edges
    protected Vector edgeOut = new Vector(INITIALSIZE, CAPINCREMENT);
    // constants needed for the constructor of java.util.Vector
    protected static final int INITIALSIZE = 10;
    protected static final int CAPINCREMENT = 10;

};