ParkingLotPuzzle

This lib simulates a RushHour puzzle created by Nob Yoshigahara: https://en.wikipedia.org/wiki/Rush_Hour_(puzzle).

You can choose from lots of preconfigured puzzles or input your custom puzzle configuration.

Known clients: .

Board definition.

Hash (#) represents the walls. Vehicles cannot move into walls.

Dot (.) represents the empty spaces. Cars can move freely into empty spaces.

Other characters represent vehicles. However, for standartization using capital letters for vehicles are encouraged. Letter A represents the main vehicle.

Goal of the game.

Move the main vehicle (A) to the right side of the board: the vehicle must be on the rightmost cell.

Example of the solved puzzle:

..BB..
C.....
C...AA
C.EKOO
DDEK..

Functionality

• Create puzzle:
  • Provide a number of moves. Get a random preconfigured puzzle solvable in provided number of moves. Note that there are no puzzles solvable in 56, 57, 59 moves. Inputting these numbers will cause error.
  • Provide a custom NxM puzzle. If invalid puzzle is provided an error will be thrown.
• Get a list of vehicles and their positions on the puzzle.
• Get width and height of the puzzle.
• Show puzzle representation.
• Get a copy of the puzzle.
• Show valid moves.
• Make a valid move. Making an invalid move will throw an error and will not result in any action.
• Check if puzzle is solved.

Library restriction

Vehicles which have a length of a single cell are not allowed since it is not clear which direction it is facing.

Usage

from parkinglotpuzzle.lot import Lot
# Create puzzle solvable in 60 moves.
lot = Lot(60)

# Create a custom puzzle.
self.valid_layout = """
....O
FF..O
.AA..
..BB.
.CC..
.DD..
"""
lot = Lot(self.valid_layout)

print(lot.query_vehicles())
# Shows vehicles and their positions: (x, y) of each occupied cell.
# {
#     'A': [(1, 2), (2, 2)],
#     'O': [(4, 0), (4, 1)],
#     'F': [(0, 1), (1, 1)],
#     'B': [(2, 3), (3, 3)],
#     'C': [(1, 4), (2, 4)],
#     'D': [(1, 5), (2, 5)]
# }

print(lot.dimensions())
# Shows (width, height) of the puzzle.

print(lot)
# Prints the puzzle:
# ....O
# FF..O
# .AA..
# ..BB.
# .CC..
# .DD..

print(lot.grid())
# ['....O', 'FF..O', '.AA..', '..BB.', '.CC..', '.DD..']

print(lot.query_legal_moves())
# Shows legal moves. Given example, moves are:
# {
#     'A': (1, 2), # Main vehicle can move 1 step back and 2 forward. 
#     'O': (0, 4), # O vehicle cannot move back and can move 4 steps forward.
#     'F': (0, 2), # F vehicle cannot move back and can move 2 steps forward.
#     'B': (2, 1), # B vehicle can move 2 steps back and a step forward.
#     'C': (1, 2), # C vehicle can move a step back and a 2 steps forward.
#     'D': (1, 2) # D vehicle can move a step back and a 2 steps forward.
# }

# Check if puzzle is solved.
print(lot.is_solved())
#False

# Make a move which solves the puzzle.
lot.move('A', 2)

print(lot)
# ....O
# FF..O
# ...AA
# ..BB.
# .CC..
# .DD..

print(lot.is_solved())
#True

Caution

Please only use str(lot) method when printing. Otherwise make use of lot.grid() method.

If you couple to str(lot) and this method will change by introducing different formatting or showing the board in a different way, your code will break.

Game configuration database

The rush_sample.txt contains a modified sample from database of game configurations created by Michael Fogleman https://www.michaelfogleman.com/rush/. Modified means o is replaced with . and x with #.

Extra sources

A good analysis of the game: https://www.michaelfogleman.com/rush/.