src/com.example.portfolio3/com/example/portfolio3/AbstractGraph.java



package com.example.portfolio3;

// origin: <https://moodle.ruc.dk/course/section.php?id=211877>

import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;

/// foo
public abstract class AbstractGraph implements Graph {

    /// foo
    AbstractGraph() { }

    /// foo
    private HashMap<String, Vertex> vertexMap = new HashMap<>();

    /// foo
    private HashSet<Vertex> vertexSet = new HashSet<>();

    /// foo
    /// @param s  foo
    /// @return   Vertex
    public final Vertex vertex(final String s) {
        if (vertexMap.containsKey(s)) {
            return vertexMap.get(s);
        }
        Vertex v = new Vertex(s);
        vertexMap.put(s, v);
        vertexSet.add(v);

        return v;
    }

    /// foo
    public final void insertEdge(
        final String v, final String u, final int w
    ) {
        insertEdge(vertex(v), vertex(u), w);
    }

    /// foo
    public final Collection<Vertex> vertices() {
        return vertexSet;
    }

    /// foo
    /// @param v1  foo
    /// @param v2  foo
    /// @param w   foo
    abstract public void insertEdge(Vertex v1, Vertex v2, int w);

    /// foo
    abstract public Collection<Edge> edges();

    /// foo
    abstract public Collection<Edge> outEdge(Vertex v);

    /// foo
    abstract public Integer getWeight(Vertex v1, Vertex v2);
}