Enforce immutability via final and unmodifiableList.
This commit is contained in:
Holt59
@@ -2,9 +2,10 @@ package org.insa.algo.weakconnectivity;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.LinkedList;
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import java.util.Queue;
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import java.util.HashSet;
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import java.util.LinkedList;
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import java.util.List;
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import java.util.Queue;
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import org.insa.algo.AbstractAlgorithm;
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import org.insa.algo.AbstractSolution.Status;
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@@ -12,146 +13,149 @@ import org.insa.graph.Arc;
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import org.insa.graph.Graph;
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import org.insa.graph.Node;
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public class WeaklyConnectedComponentsAlgorithm extends AbstractAlgorithm<WeaklyConnectedComponentObserver>{
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public class WeaklyConnectedComponentsAlgorithm extends AbstractAlgorithm<WeaklyConnectedComponentObserver> {
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/**
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*
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* @param instance
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* @param logOutput
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*/
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public WeaklyConnectedComponentsAlgorithm(WeaklyConnectedComponentsData instance) {
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super(instance);
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}
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@Override
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public WeaklyConnectedComponentsSolution run() {
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return (WeaklyConnectedComponentsSolution)super.run();
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}
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@Override
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public WeaklyConnectedComponentsData getInstance() {
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return (WeaklyConnectedComponentsData)super.getInstance();
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}
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/**
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* Notify all observers that the algorithm is entering a new component.
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*
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* @param curNode Starting node for the component.
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*/
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protected void notifyStartComponent(Node curNode) {
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for (WeaklyConnectedComponentObserver obs: getObservers()) {
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obs.notifyStartComponent(curNode);
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}
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}
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/**
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* Notify all observers that a new node has been found for the current component.
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*
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* @param node New node found for the current component.
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*/
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protected void notifyNewNodeInComponent(Node node) {
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for (WeaklyConnectedComponentObserver obs: getObservers()) {
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obs.notifyNewNodeInComponent(node);
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}
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}
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/**
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* Notify all observers that the algorithm has computed a new component.
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*
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* @param nodes List of nodes in the component.
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*/
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protected void notifyEndComponent(ArrayList<Node> nodes) {
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for (WeaklyConnectedComponentObserver obs: getObservers()) {
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obs.notifyEndComponent(nodes);
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}
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}
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/**
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* @return An adjacency list for the undirected graph equivalent to the stored graph.
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*/
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protected ArrayList<HashSet<Integer>> createUndirectedGraph() {
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int nNodes = getInstance().getGraph().getNodes().size();
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ArrayList<HashSet<Integer>> res = new ArrayList<HashSet<Integer>>(nNodes);
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for (int i = 0; i < nNodes; ++i) {
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res.add(new HashSet<Integer>());
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}
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for (Node node: getInstance().getGraph().getNodes()) {
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for (Arc arc: node.getSuccessors()) {
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res.get(node.getId()).add(arc.getDestination().getId());
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if (arc.getInfo().isOneWay()) {
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res.get(arc.getDestination().getId()).add(node.getId());
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}
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}
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}
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return res;
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}
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/**
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* Apply a breadth first search algorithm on the given undirected graph (adjacency list),
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* starting at node cur, and marking nodes in marked.
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*
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* @param marked
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* @param cur
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*
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* @return
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*/
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protected ArrayList<Node> bfs(ArrayList<HashSet<Integer>> ugraph, boolean[] marked, int cur) {
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ArrayList<Node> nodes = getInstance().getGraph().getNodes();
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ArrayList<Node> component = new ArrayList<Node>();
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// Using a queue because we are doing a BFS
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Queue<Integer> queue = new LinkedList<Integer>();
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/**
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*
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* @param instance
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* @param logOutput
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*/
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public WeaklyConnectedComponentsAlgorithm(WeaklyConnectedComponentsData instance) {
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super(instance);
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}
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// Notify observers about the current component.
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notifyStartComponent(nodes.get(cur));
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// Add original node and loop until the queue is empty.
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queue.add(cur);
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marked[cur] = true;
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while (!queue.isEmpty()) {
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Node node = nodes.get(queue.remove());
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component.add(node);
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// Notify observers
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notifyNewNodeInComponent(node);
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for (Integer destId: ugraph.get(node.getId())) {
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Node dest = nodes.get(destId);
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if (!marked[dest.getId()]) {
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queue.add(destId);
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marked[destId] = true;
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}
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}
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}
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notifyEndComponent(component);
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return component;
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}
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@Override
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public WeaklyConnectedComponentsSolution run() {
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return (WeaklyConnectedComponentsSolution) super.run();
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}
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@Override
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protected WeaklyConnectedComponentsSolution doRun() {
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Graph graph = getInstance().getGraph();
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ArrayList<HashSet<Integer>> ugraph = createUndirectedGraph();
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boolean[] marked = new boolean[graph.getNodes().size()];
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Arrays.fill(marked, false);
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ArrayList<ArrayList<Node>> components = new ArrayList<ArrayList<Node>>();
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// perform algorithm
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int cur = 0;
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while (cur < marked.length) {
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// Apply BFS
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components.add(this.bfs(ugraph, marked, cur));
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// Find next non-marked
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for (; cur < marked.length && marked[cur]; ++cur);
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}
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return new WeaklyConnectedComponentsSolution(getInstance(), Status.OPTIMAL, components);
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}
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@Override
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public WeaklyConnectedComponentsData getInstance() {
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return (WeaklyConnectedComponentsData) super.getInstance();
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}
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/**
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* Notify all observers that the algorithm is entering a new component.
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*
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* @param curNode Starting node for the component.
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*/
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protected void notifyStartComponent(Node curNode) {
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for (WeaklyConnectedComponentObserver obs: getObservers()) {
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obs.notifyStartComponent(curNode);
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}
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}
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/**
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* Notify all observers that a new node has been found for the current
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* component.
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*
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* @param node New node found for the current component.
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*/
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protected void notifyNewNodeInComponent(Node node) {
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for (WeaklyConnectedComponentObserver obs: getObservers()) {
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obs.notifyNewNodeInComponent(node);
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}
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}
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/**
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* Notify all observers that the algorithm has computed a new component.
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*
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* @param nodes List of nodes in the component.
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*/
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protected void notifyEndComponent(ArrayList<Node> nodes) {
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for (WeaklyConnectedComponentObserver obs: getObservers()) {
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obs.notifyEndComponent(nodes);
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}
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}
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/**
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* @return An adjacency list for the undirected graph equivalent to the stored
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* graph.
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*/
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protected ArrayList<HashSet<Integer>> createUndirectedGraph() {
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int nNodes = getInstance().getGraph().getNodes().size();
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ArrayList<HashSet<Integer>> res = new ArrayList<HashSet<Integer>>(nNodes);
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for (int i = 0; i < nNodes; ++i) {
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res.add(new HashSet<Integer>());
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}
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for (Node node: getInstance().getGraph().getNodes()) {
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for (Arc arc: node.getSuccessors()) {
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res.get(node.getId()).add(arc.getDestination().getId());
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if (arc.getInfo().isOneWay()) {
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res.get(arc.getDestination().getId()).add(node.getId());
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}
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}
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}
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return res;
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}
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/**
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* Apply a breadth first search algorithm on the given undirected graph
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* (adjacency list), starting at node cur, and marking nodes in marked.
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*
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* @param marked
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* @param cur
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*
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* @return
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*/
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protected ArrayList<Node> bfs(ArrayList<HashSet<Integer>> ugraph, boolean[] marked, int cur) {
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List<Node> nodes = getInstance().getGraph().getNodes();
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ArrayList<Node> component = new ArrayList<Node>();
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// Using a queue because we are doing a BFS
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Queue<Integer> queue = new LinkedList<Integer>();
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// Notify observers about the current component.
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notifyStartComponent(nodes.get(cur));
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// Add original node and loop until the queue is empty.
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queue.add(cur);
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marked[cur] = true;
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while (!queue.isEmpty()) {
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Node node = nodes.get(queue.remove());
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component.add(node);
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// Notify observers
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notifyNewNodeInComponent(node);
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for (Integer destId: ugraph.get(node.getId())) {
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Node dest = nodes.get(destId);
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if (!marked[dest.getId()]) {
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queue.add(destId);
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marked[destId] = true;
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}
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}
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}
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notifyEndComponent(component);
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return component;
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}
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@Override
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protected WeaklyConnectedComponentsSolution doRun() {
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Graph graph = getInstance().getGraph();
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ArrayList<HashSet<Integer>> ugraph = createUndirectedGraph();
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boolean[] marked = new boolean[graph.getNodes().size()];
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Arrays.fill(marked, false);
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ArrayList<ArrayList<Node>> components = new ArrayList<ArrayList<Node>>();
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// perform algorithm
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int cur = 0;
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while (cur < marked.length) {
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// Apply BFS
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components.add(this.bfs(ugraph, marked, cur));
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// Find next non-marked
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for (; cur < marked.length && marked[cur]; ++cur)
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;
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}
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return new WeaklyConnectedComponentsSolution(getInstance(), Status.OPTIMAL, components);
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}
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}
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