110 lines
2.7 KiB
Python
110 lines
2.7 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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Safe cracking puzzle in Google CP Solver.
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From the Oz Primer:
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http://www.comp.nus.edu.sg/~henz/projects/puzzles/digits/index.html
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'''
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The code of Professor Smart's safe is a sequence of 9 distinct
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nonzero digits C1 .. C9 such that the following equations and
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inequations are satisfied:
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C4 - C6 = C7
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C1 * C2 * C3 = C8 + C9
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C2 + C3 + C6 < C8
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C9 < C8
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and
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C1 <> 1, C2 <> 2, ..., C9 <> 9
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can you find the correct combination?
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'''
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Compare with the following models:
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* MiniZinc: http://www.hakank.org/minizinc/safe_cracking.mzn
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* ECLiPSe : http://www.hakank.org/eclipse/safe_cracking.ecl
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* SICStus : http://www.hakank.org/sicstus/safe_cracking.pl
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* Gecode: http://hakank.org/gecode/safe_cracking.cpp
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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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from constraint_solver import pywrapcp
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def main():
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# Create the solver.
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solver = pywrapcp.Solver('Safe cracking puzzle')
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#
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# data
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#
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n = 9
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digits = range(1,n+1)
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#
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# variables
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#
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LD = [solver.IntVar(digits, 'LD[%i]'%i) for i in range(n)]
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C1,C2,C3,C4,C5,C6,C7,C8,C9 = LD
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#
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# constraints
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#
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solver.Add(solver.AllDifferent(LD))
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solver.Add(C4 - C6 == C7)
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solver.Add(C1 * C2 * C3 == C8 + C9)
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solver.Add(C2 + C3 + C6 < C8)
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solver.Add(C9 < C8)
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for i in range(n):
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solver.Add(LD[i] != i+1)
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#
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# search and result
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#
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db = solver.Phase(LD,
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solver.INT_VAR_DEFAULT,
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solver.INT_VALUE_DEFAULT
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)
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solver.NewSearch(db)
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num_solutions = 0
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while solver.NextSolution():
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num_solutions += 1
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print 'LD:', [LD[i].Value() for i in range(n)]
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solver.EndSearch()
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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(), 'ms'
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if __name__ == '__main__':
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main()
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