Subversion Repositories programming

#!/usr/bin/env python

__author__    = "Ira W. Snyder (devel@irasnyder.com)"
__copyright__ = "Copyright (c) 2006 Ira W. Snyder (devel@irasnyder.com)"
__license__   = "GNU GPL v2 (or, at your option, any later version)"

from Generator import Generator


class PuzzleGenerator (Generator):

        EMPTY = 'E'

        def get_children (self):
                children = []
                empty_pos = self.find_empty_pos ()

                # Get the correct moves for this position
                fn = {  0 : (self.move_down,  self.move_right),
                        1 : (self.move_down,  self.move_left,  self.move_right),
                        2 : (self.move_down,  self.move_left),
                        3 : (self.move_down,  self.move_right, self.move_up),
                        4 : (self.move_down,  self.move_left,  self.move_right, self.move_up),
                        5 : (self.move_down,  self.move_left,  self.move_up),
                        6 : (self.move_right, self.move_up),
                        7 : (self.move_left,  self.move_right, self.move_up),
                        8 : (self.move_left,  self.move_up) }[empty_pos]

                # Call each of the proper functions
                for f in fn:
                        children.append (f (empty_pos))

                # Return the created list
                return children

        def find_empty_pos (self):
                for i in xrange (len (self.value)):
                        if self.value[i] == self.EMPTY:
                                return i

                raise ValueError

        def move_up (self, empty_pos):
                copy = self.value[:]
                copy[empty_pos] = copy[empty_pos - 3]
                copy[empty_pos - 3] = self.EMPTY
                return copy

        def move_left (self, empty_pos):
                copy = self.value[:]
                copy[empty_pos] = copy[empty_pos - 1]
                copy[empty_pos - 1] = self.EMPTY
                return copy

        def move_right (self, empty_pos):
                copy = self.value[:]
                copy[empty_pos] = copy[empty_pos + 1]
                copy[empty_pos + 1] = self.EMPTY
                return copy

        def move_down (self, empty_pos):
                copy = self.value[:]
                copy[empty_pos] = copy[empty_pos + 3]
                copy[empty_pos + 3] = self.EMPTY
                return copy



def printpuz (state):
        for i in xrange(3):
                for j in xrange(3):
                        print '%s ' % (str(state[(3*i)+j]), ) ,

                print

def main ():

        #initial = [1, 2, 3, 4, PuzzleGenerator.EMPTY, 5, 6, 7, 8]
        initial = [PuzzleGenerator.EMPTY, 2, 3, 4, 1, 5, 6, 7, 8]

        print 'Initial State:'
        printpuz (initial)
        print

        print 'Children:'
        p = PuzzleGenerator(initial)
        for c in p.get_children ():
                printpuz (c)
                print

if __name__ == '__main__':
        main ()