package dfs;

import java.util.Set;
/**
 *
 * @author Oleg
 */
public class DFS {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {

    }

    public static int findWay(Graph g, Vertex start, Vertex end)
    {
        Set<Vertex> old = new Set<Vertex>();
        int length = nextStep(start, old, 0);
        return length;
    }

    public static int nextStep(Vertex v, Set<Vertex> old, int length) {
        int maxLength = length + 1;
        for (Vertex neighbor : v.getNeighbors()) {
            if (neighbor.equals(end)) {
                return maxLength + 1;
            }
            if (!old.contains(neighbor)) {
                old.add(neighbor);
                int l = nextStep(neighbor);
                if (l > maxLength) {
                    maxLength = l;
                }
            }
        }
    }

}