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;
    }
}

public class CodeJamLineParser {
	private final String[] tokens;
	private int position;
	
	public CodeJamLineParser(String line) {
		tokens = line.split("\\s");
		position = 0;
	}
	
	public boolean hasNextField() {
		return hasNextFields(1);
	}
	
	public int remainingFields() {
		return tokens.length - position;
	}
	
	public boolean hasNextFields(int count) {
		return remainingFields() >= count;
	}
	
	public String readNextStr() {
		return tokens[position++];
	}
	
	public int readNextInt() {
		return Integer.parseInt(readNextStr());
	}
	
	public int[] readNextIntList(int numOfInts) {
		int[] result = new int[numOfInts];
		for (int i = 0; i < numOfInts; ++i) {
			result[i] = readNextInt();
		}
		return result;
	}
}
