import java.util.*;
import java.util.concurrent.*;


public class ParkingLot{

    private Map<Pair<Integer>,Date> park;
    private LinkedList<Pair<Integer>> occupPark;
    private int i;
    private int j;
    private int m;
    private int n;
    private int maxCars;

    public ParkingLot (int n,int m){
        this.n=n;
        this.m=m;
        maxCars=n*m;
        park = new HashMap<>();
        occupPark = new LinkedList<>();


    }
    public synchronized Pair<Integer> carIn(){

        Pair<Integer> pos;
        //Parcheggio Pieno
        if(maxCars<=0) return null;
        // Ci sono posti liberi "non continui"
        if (occupPark.size()>0){

            pos = occupPark.removeFirst();
            park.put(pos,new Date());
            maxCars--;
            return pos;
        }
        pos = new Pair<Integer> (i,j);
        park.put(pos,new Date());
        maxCars--;

        if(j==m && i!=n){
            j=0;
            i++;
        }
        else j++;
        return pos;

    }

    public int getMax(){return maxCars;}

    public synchronized Integer carOut(Pair pos){

        Date currDate = new Date();
        Set<Pair<Integer>> set = park.keySet();
        if(!set.contains(pos)) return null;
        Date carDate = park.get(pos);
        set.remove(pos);
        occupPark.add(pos);
        maxCars++;
        return currDate.getSeconds() - carDate.getSeconds();

   }

    public static void main(String[] args){

       final ParkingLot p =new ParkingLot(10,10);
        BlockingQueue<Pair<Integer>> cars = new LinkedBlockingQueue<>();

        Thread abusivo = new Thread(){

            @Override
            public void run(){
                Pair<Integer> pos;
                synchronized(cars){
                    // Ci sono ancora posti auto
                    while(p.getMax()>0){
                            try{
                                cars.wait(1000);
                                cars.add(p.carIn());
                                cars.notifyAll();
                            }catch(InterruptedException e){}

                    }

                    cars.notifyAll();
                }
            }
         };

        Thread finanza = new Thread(){
            @Override
            public void run(){
                synchronized(cars){
                    while(cars.size()>0 ){
                   try{

                         cars.wait(1000);
                         System.out.println(p.carOut(cars.take()));
                         cars.notifyAll();

                     }

                 catch(InterruptedException e){}
                }
            }
            cars.notifyAll();

            }
         };

        try{
        abusivo.start();
        finanza.start();
        abusivo.join();
        finanza.join();
        }
        catch(InterruptedException e){}


}


}