117 lines
2.9 KiB
Python
117 lines
2.9 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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Olympic puzzle in Google CP Solver.
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Benchmark for Prolog (BProlog)
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'''
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File : olympic.pl
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Author : Neng-Fa ZHOU
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Date : 1993
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Purpose: solve a puzzle taken from Olympic Arithmetic Contest
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Given ten variables with the following configuration:
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X7 X8 X9 X10
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X4 X5 X6
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X2 X3
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X1
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We already know that X1 is equal to 3 and want to assign each variable
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with a different integer from {1,2,...,10} such that for any three
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variables
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Xi Xj
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Xk
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the following constraint is satisfied:
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|Xi-Xj| = Xk
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'''
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Compare with the following models:
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* MiniZinc: http://www.hakank.org/minizinc/olympic.mzn
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* SICStus Prolog: http://www.hakank.org/sicstus/olympic.pl
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* ECLiPSe: http://hakank.org/eclipse/olympic.ecl
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* Gecode: http://hakank.org/gecode/olympic.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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import sys
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from ortools.constraint_solver import pywrapcp
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def minus(solver, x, y, z):
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solver.Add(z == abs(x - y))
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def main():
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# Create the solver.
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solver = pywrapcp.Solver('Olympic')
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#
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# data
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#
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n = 10
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#
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# declare variables
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#
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Vars = [solver.IntVar(1, n, 'Vars[%i]' % i) for i in range(n)]
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X1,X2,X3,X4,X5,X6,X7,X8,X9,X10 = Vars
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#
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# constraints
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#
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solver.Add(solver.AllDifferent(Vars))
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solver.Add(X1 == 3)
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minus(solver, X2, X3, X1)
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minus(solver, X4, X5, X2)
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minus(solver, X5, X6, X3)
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minus(solver, X7, X8, X4)
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minus(solver, X8, X9, X5)
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minus(solver, X9, X10, X6)
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#
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# solution and search
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#
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db = solver.Phase(Vars,
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solver.INT_VAR_SIMPLE,
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solver.INT_VALUE_DEFAULT)
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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 'Vars:', [Vars[i].Value() for i in range(n)]
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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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