package util.graph;

import java.util.HashSet;
import java.util.PriorityQueue;
import java.util.Set;

public class DynDjikstra {
    public static State FindShortest(Node start, Node target) {
        PriorityQueue<Node> openSet = new PriorityQueue<>();
        Set<Node> closedSet = new HashSet<>();
        openSet.add(start);
        while (!openSet.isEmpty()) {
            Node current = openSet.poll();
            for (Edge edge : current.edges) {
                Node end = edge.target;
                if (closedSet.contains(end)) {
                    continue;
                }
                State newState = edge.travel(current.last);
                //if (end.equals(target)) {
                    //return newState;
                //}
                if (openSet.contains(end)) {
                    if (end.last.compareTo(newState)>0) {
                        end.last = newState;
                    }
                } else {
                    openSet.add(end);
                    end.last = newState;
                }
            }
            closedSet.add(current);
            if (closedSet.contains(target)) {
                return target.last;
            }
        }

        return target.last;
    }
}

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;


public class ProblemUtils {

	public static String[] readInput(String path) throws Exception {
		FileInputStream in = new FileInputStream(path);
		BufferedReader reader = new BufferedReader(new InputStreamReader(in));
		int nlines = Integer.parseInt(reader.readLine());
		String[] lines = new String[nlines];
		for (int i = 0; i < nlines; i++) {
			lines[i] = reader.readLine();
		}
		return lines;
	}
	
	public static void writeOutput(String path, String[] lines) throws Exception {
		FileOutputStream out = new FileOutputStream(path);
		BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(out));
		for (int i = 0; i < lines.length; i++) {
			writer.write("Case #" + (i + 1) + ": " + lines[i]);
			if (i + 1 < lines.length) {
				writer.write("\n");
			}
		}
		writer.flush();
		out.close();
	}
	
}
