/**
 * Copyright 2007 Troy Korjuslommi.
 * All Rights Reserved.
 * Released under GNU License version 2.
 * See http://www.gnu.org/
 */
import java.util.List;
import java.util.Vector;


public class SeatShuffle {
	private int mVerbose;
	private List<Seat> mSeats;
	private List<Passenger> mPassengers;


	static public void main(String argv[]) {
		final int seats = 100;
		int n = 0;
		int times = 1;
		int verbose = 0;
		for (int i = 0, ii = argv.length; i < ii; i++) {
			if (argv[i].equals("-v1"))
				verbose = 1;
			else if (argv[i].equals("-v2"))
				verbose = 2;
			else if (argv[i].equals("-v3"))
				verbose = 3;
			else if (argv[i].equals("-t") && i+1 < ii) {
				try {
					times = Integer.parseInt(argv[++i]);
				} catch (NumberFormatException ex) {
					System.err.println("Bad argument to -t.");
					System.exit(-1);
				}
			}
			else {
					System.err.println("Usage: SeatShuffle [-v1 -v2 -v3] [-t number]");
					System.err.println("\t-v1 : verbosity level 1.");
					System.err.println("\t-v2 : verbosity level 2.");
					System.err.println("\t-v3 : verbosity level 3.");
					System.err.println("\t-t : number of times to board passengers on the plane.");
					System.exit(-1);
			}
		}
		for (int i = 0; i < times; i++) {
			SeatShuffle l = new SeatShuffle(seats, verbose);
			if (l.play())
				n++;
		}
		System.err.println("Got the right seat on " + n + "/" + times + " flights.");
	}


	public SeatShuffle(int seats, int verbose) {
		mVerbose = verbose;
		mSeats = new Vector<Seat>(seats);
		mPassengers = new Vector<Passenger>(seats);
		for (int i = 0; i < seats; i++) {
			mSeats.add(new Seat(i+1));
		}
		try {
			for (int i = 0; i < seats; i++) {
				int sn = getRandomUnreservedSeatNumber();
				getSeatByNumber(sn).makeReservation();
				mPassengers.add(new Passenger(i == 0, sn));
			}
		} catch (SeatShuffleException ex) {
			System.err.println("ERROR2: " + ex.getMessage());
		}
	}


	int getRandomUnreservedSeatNumber() {
		double seatcount = (double)mSeats.size();
		while (true) {
			int n = (int)Math.floor(Math.random() * seatcount);
			n++;
			if (! getSeatByNumber(n).isReserved())
				return n;
		}
	}


	int getRandomUnoccupiedSeatNumber() {
		double seatcount = (double)mSeats.size();
		while (true) {
			int n = (int)Math.floor(Math.random() * seatcount);
			n++;
			if (! getSeatByNumber(n).isOccupied())
				return n;
		}
	}



	boolean play() {
		try {
			for (int i = 0, ii = mPassengers.size(); i < ii; i++) {
				mPassengers.get(i).sit();
				boolean b = mPassengers.get(i).checkSeat(i+1 == ii);
				if (i+1 == ii)
					return b;
			}
			throw new SeatShuffleException("End of loop?");
		} catch (SeatShuffleException ex) {
			System.err.println("ERROR: " + ex.getMessage());
		}
		return false;
	}

	Seat getSeatByNumber(int num) {
		return mSeats.get(num-1);
	}


	class Passenger {
		private boolean mIsLuny;
		private int mReservation;
		private Seat mSeat;

		Passenger(boolean isluny, int reservation) {
			mIsLuny = isluny;
			mReservation = reservation;
		}

		void sit() throws SeatShuffleException {
			Seat seat = getSeatByNumber(mReservation);
			if (mIsLuny || seat.isOccupied()) {
				seat = getSeatByNumber(getRandomUnoccupiedSeatNumber());
			}
			seat.occupy(this);
			mSeat = seat;
		}

		boolean checkSeat(boolean islast) {
			boolean seatRight = mSeat.getNumber() == mReservation;
			if (mVerbose > 2 || ! seatRight && mVerbose > 1 || (mVerbose > 0 && islast)) {
				System.err.print("I am passenger nr. " + mReservation + " in seat " + mSeat.getNumber() + ". I am sitting in the " + ((seatRight) ? "right" : "wrong") + " seat.");
				if (mIsLuny)
					System.err.print(" I am the LUNY.");
				if (islast)
					System.err.println(" I am the LAST passenger in.");
				else
					System.err.println("");
			}
			return seatRight;
		}
	}

	class Seat {
		private int mNumber;
		private Passenger mPassenger;
		private boolean mIsReserved;

		Seat(int num) {
			mNumber = num;
		}

		void makeReservation() throws SeatShuffleException {
			if (mIsReserved)
				throw new SeatShuffleException("Seat reserved. Cannot reserve.");
			mIsReserved = true;
		}

		boolean isReserved() {
			return mIsReserved;
		}

		int getNumber() {
			return mNumber;
		}

		void occupy(Passenger p) throws SeatShuffleException {
			if (mPassenger != null)
				throw new SeatShuffleException("Cannot occupy. Seat used.");
			mPassenger = p;
		}

		boolean isOccupied() {
			return (mPassenger != null);
		}
	}

	class SeatShuffleException extends Exception {
		SeatShuffleException(String msg) {
			super(msg);
		}
	}

}