242 lines
6.4 KiB
Python
242 lines
6.4 KiB
Python
# Copyright 2010 Hakan Kjellerstrand hakank@bonetmail.com
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""
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Minesweeper in Google CP Solver.
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From gecode/examples/minesweeper.cc:
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'''
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A specification is a square matrix of characters. Alphanumeric
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characters represent the number of mines adjacent to that field.
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Dots represent fields with an unknown number of mines adjacent to
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it (or an actual mine).
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'''
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E.g.
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'..2.3.'
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'2.....'
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'..24.3'
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'1.34..'
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'.....3'
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'.3.3..'
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Also see:
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* http://www.janko.at/Raetsel/Minesweeper/index.htm
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* http://en.wikipedia.org/wiki/Minesweeper_(computer_game)
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* Ian Stewart on Minesweeper:
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http://www.claymath.org/Popular_Lectures/Minesweeper/
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* Richard Kaye's Minesweeper Pages
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http://web.mat.bham.ac.uk/R.W.Kaye/minesw/minesw.htm
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* Some Minesweeper Configurations
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http://web.mat.bham.ac.uk/R.W.Kaye/minesw/minesw.pdf
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Compare with the following models:
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* MiniZinc: http://www.hakank.org/minizinc/minesweeper.mzn
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* Choco : http://www.hakank.org/choco/MineSweeper.java
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* JaCoP : http://www.hakank.org/JaCoP/MineSweeper.java
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* Gecode/R: http://www.hakank.org/gecode_r/minesweeper.rb
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* Comet : http://www.hakank.org/comet/minesweeper.co
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* ECLiPSe : http://www.hakank.org/eclipse/minesweeper.ecl
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* SICStus : http://www.hakank.org/sicstus/minesweeper.pl
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* Tailor/Essence': http://www.hakank.org/tailor/minesweeper.eprime
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* Zinc: http://www.hakank.org/minizinc/minesweeper.zinc
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This model was created by Hakan Kjellerstrand (hakank@bonetmail.com)
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Also see my other Google CP Solver models: http://www.hakank.org/google_or_tools/
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"""
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import sys
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from ortools.constraint_solver import pywrapcp
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default_r = 8
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default_c = 8
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X = -1
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default_game = [
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[2,3,X,2,2,X,2,1],
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[X,X,4,X,X,4,X,2],
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[X,X,X,X,X,X,4,X],
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[X,5,X,6,X,X,X,2],
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[2,X,X,X,5,5,X,2],
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[1,3,4,X,X,X,4,X],
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[0,1,X,4,X,X,X,3],
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[0,1,2,X,2,3,X,2]
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]
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def main(game="", r="", c=""):
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# Create the solver.
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solver = pywrapcp.Solver('Minesweeper')
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#
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# data
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#
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# Set default problem
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if game == "":
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game = default_game
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r = default_r
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c = default_c
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else:
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print "rows:", r, " cols:", c
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#
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# Default problem from "Some Minesweeper Configurations",page 3
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# (same as problem instance minesweeper_config3.txt)
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# It has 4 solutions
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#
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# r = 8
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# c = 8
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# X = -1
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# game = [
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# [2,3,X,2,2,X,2,1],
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# [X,X,4,X,X,4,X,2],
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# [X,X,X,X,X,X,4,X],
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# [X,5,X,6,X,X,X,2],
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# [2,X,X,X,5,5,X,2],
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# [1,3,4,X,X,X,4,X],
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# [0,1,X,4,X,X,X,3],
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# [0,1,2,X,2,3,X,2]
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# ]
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S = [-1,0,1] # for the neighbors of "this" cell
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# print problem instance
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print "Problem:"
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for i in range(r):
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for j in range(c):
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if game[i][j] == X:
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print "X",
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else:
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print game[i][j],
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print
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print
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# declare variables
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mines = {}
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for i in range(r):
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for j in range(c):
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mines[(i,j)] = solver.IntVar(0,1, 'mines %i %i' % (i, j))
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#
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# constraints
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#
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for i in range(r):
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for j in range(c):
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if game[i][j] >= 0:
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solver.Add(mines[i,j] == 0)
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# this cell is the sum of all the surrounding cells
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solver.Add(
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game[i][j] == solver.Sum([mines[i+a,j+b]
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for a in S for b in S
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if i + a >=0 and
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j + b >=0 and
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i + a < r and
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j + b < c
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])
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)
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if game[i][j] > X:
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# This cell cannot be a mine
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solver.Add(mines[i,j] == 0)
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#
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# solution and search
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#
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solution = solver.Assignment()
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solution.Add([mines[(i,j)] for i in range(r) for j in range(c)])
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collector = solver.AllSolutionCollector(solution)
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solver.Solve(solver.Phase([mines[(i,j)] for i in range(r) for j in range(c)],
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solver.INT_VAR_SIMPLE,
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solver.ASSIGN_MIN_VALUE),
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[collector])
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num_solutions = collector.SolutionCount()
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print "num_solutions: ", num_solutions
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if num_solutions > 0:
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for s in range(num_solutions):
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minesval = [collector.Value(s, mines[(i,j)])
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for i in range(r) for j in range(c)]
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for i in range(r):
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for j in range(c):
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print minesval[i*c+j],
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print
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print
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print
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print "num_solutions:", num_solutions
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print "failures:", solver.Failures()
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print "branches:", solver.Branches()
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print "WallTime:", solver.WallTime()
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else:
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print "No solutions found"
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#
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# Read a problem instance from a file
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#
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def read_problem(file):
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f = open(file, 'r')
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rows = int(f.readline())
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cols = int(f.readline())
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game = []
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for i in range(rows):
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x = f.readline()
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row = [0]*cols
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for j in range(cols):
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if x[j] == ".":
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tmp = -1
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else:
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tmp = int(x[j])
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row[j] = tmp
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game.append(row)
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return [game, rows, cols]
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#
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# Print the mines
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#
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def print_mines(mines, rows, cols):
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for i in range(rows):
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for j in range(cols):
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print mines[i,j],
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print ''
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def print_game(game, rows, cols):
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for i in range(rows):
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for j in range(cols):
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print game[i][j],
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print ''
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if __name__ == '__main__':
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if len(sys.argv) > 1:
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file = sys.argv[1]
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print "Problem instance from", file
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[game, rows, cols] = read_problem(file)
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# print_game(game, rows, cols)
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main(game, rows, cols)
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else:
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main()
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