Node.java

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

public class Node {
	public enum Status {
		COMPLETE,
		INPROGRESS,
		UNSEEN,
	}

	public int id;
	public int index;
	public int lowlink;
	public Status status;
	public Search search;
	public ArrayList<Search> blocked;

	public Node(int id, int index, int lowlink) {
		this.id = id;
		this.index = index;
		this.lowlink = lowlink;
		this.status = Status.UNSEEN;
		this.blocked = new ArrayList<>();
		this.search = null;
	}

	public void updateLowLink(int update) {
		this.lowlink = Math.min(this.lowlink, update);
	}

	// Transfere o nó para uma nova busca, atualizando o índice, lowlink e a busca
	public synchronized int tranfer(int deltaIndex, Search newSearch) {
		this.index += deltaIndex;
		this.lowlink += deltaIndex;
		this.search = newSearch;

		return this.index;
	}

	// Retorna um HashMap com todos os nós do grafo
    public static HashMap<Integer, Node> getNodeMap(Set<Integer> nodes) {
        HashMap<Integer, Node> nodeMap = new HashMap<>();

        for(int nodeId : nodes)
            nodeMap.put(nodeId, new Node(nodeId, -1, -1));
        
        return nodeMap;
    }

	// Retorna o próximo nó não visitado
	public static Node getNotInSCC(Map<Integer, Node> nodes, Integer nextNode) {
		long maxId = nodes.keySet().stream().max(Integer::compare).get();

		if(nextNode > maxId)
			return null;
		
		Node node = nodes.get(nextNode);

		while(nextNode <= maxId) {
			if(node != null && node.status == Status.UNSEEN)
				return node;
			
			nextNode++;
			node = nodes.get(nextNode);
		}

		return null;
	}
}