8927b03942
Some of these imports are not used. The rest of them only import string to use the string.atoi function. But string.atoi(s) on a string input is identical to just int(s). See the docs: "deprecated since 2.0".
234 lines
5.9 KiB
Python
234 lines
5.9 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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Stable marriage problem in Google CP Solver.
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Problem and OPL model from Pascal Van Hentenryck
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'The OPL Optimization Programming Language', page 43ff.
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Also, see
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http://www.comp.rgu.ac.uk/staff/ha/ZCSP/additional_problems/stable_marriage/stable_marriage.pdf
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Note: This model is translated from my Comet model
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http://www.hakank.org/comet/stable_marriage.co
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I have kept some of the constraint from that code.
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Compare with the following models:
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* MiniZinc: http://www.hakank.org/minizinc/stable_marriage.mzn
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* Comet : http://www.hakank.org/comet/stable_marriage.co
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* ECLiPSe : http://www.hakank.org/eclipse/stable_marriage.ecl
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* Gecode : http://hakank.org/gecode/stable_marriage.cpp
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* SICStus : http://hakank.org/sicstus/stable_marriage.pl
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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:
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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 main(ranks, problem_name):
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# Create the solver
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solver = pywrapcp.Solver("Stable marriage")
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#
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# data
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#
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print "Problem name:", problem_name
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rankMen = ranks["rankMen"]
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rankWomen = ranks["rankWomen"]
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n = len(rankMen)
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#
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# declare variables
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#
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wife = [solver.IntVar(0, n - 1, "wife[%i]" % i) for i in range(n)]
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husband = [solver.IntVar(0, n - 1, "husband[%i]" % i) for i in range(n)]
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#
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# constraints
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#
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# forall(m in Men)
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# cp.post(husband[wife[m]] == m);
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for m in range(n):
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solver.Add(solver.Element(husband, wife[m]) == m)
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# forall(w in Women)
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# cp.post(wife[husband[w]] == w);
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for w in range(n):
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solver.Add(solver.Element(wife, husband[w]) == w)
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# forall(m in Men, o in Women)
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# cp.post(rankMen[m,o] < rankMen[m, wife[m]] => rankWomen[o,husband[o]] <
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# rankWomen[o,m]);
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for m in range(n):
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for o in range(n):
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b1 = solver.IsGreaterCstVar(
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solver.Element(rankMen[m], wife[m]), rankMen[m][o])
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b2 = (
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solver.IsLessCstVar(
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solver.Element(rankWomen[o], husband[o]), rankWomen[o][m]))
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solver.Add(b1 - b2 <= 0)
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# forall(w in Women, o in Men)
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# cp.post(rankWomen[w,o] < rankWomen[w,husband[w]] => rankMen[o,wife[o]] <
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# rankMen[o,w]);
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for w in range(n):
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for o in range(n):
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b1 = solver.IsGreaterCstVar(
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solver.Element(rankWomen[w], husband[w]), rankWomen[w][o])
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b2 = solver.IsLessCstVar(
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solver.Element(rankMen[o], wife[o]), rankMen[o][w])
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solver.Add(b1 - b2 <= 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(wife)
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solution.Add(husband)
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db = solver.Phase(wife + husband,
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solver.CHOOSE_FIRST_UNBOUND,
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solver.ASSIGN_MIN_VALUE)
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solver.NewSearch(db)
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num_solutions = 0
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solutions = []
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while solver.NextSolution():
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# solutions.append([x[i].Value() for i in range(x_len)])
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print "wife : ", [wife[i].Value() for i in range(n)]
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print "husband: ", [husband[i].Value() for i in range(n)]
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print
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num_solutions += 1
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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()
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print "#############"
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print
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#
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# From Van Hentenryck's OPL book
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#
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van_hentenryck = {
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"rankWomen": [
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[1, 2, 4, 3, 5],
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[3, 5, 1, 2, 4],
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[5, 4, 2, 1, 3],
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[1, 3, 5, 4, 2],
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[4, 2, 3, 5, 1]
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],
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"rankMen": [
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[5, 1, 2, 4, 3],
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[4, 1, 3, 2, 5],
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[5, 3, 2, 4, 1],
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[1, 5, 4, 3, 2],
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[4, 3, 2, 1, 5]
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]
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}
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#
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# Data from MathWorld
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# http://mathworld.wolfram.com/StableMarriageProblem.html
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#
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mathworld = {
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"rankWomen": [
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[3, 1, 5, 2, 8, 7, 6, 9, 4],
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[9, 4, 8, 1, 7, 6, 3, 2, 5],
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[3, 1, 8, 9, 5, 4, 2, 6, 7],
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[8, 7, 5, 3, 2, 6, 4, 9, 1],
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[6, 9, 2, 5, 1, 4, 7, 3, 8],
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[2, 4, 5, 1, 6, 8, 3, 9, 7],
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[9, 3, 8, 2, 7, 5, 4, 6, 1],
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[6, 3, 2, 1, 8, 4, 5, 9, 7],
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[8, 2, 6, 4, 9, 1, 3, 7, 5]],
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"rankMen": [
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[7, 3, 8, 9, 6, 4, 2, 1, 5],
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[5, 4, 8, 3, 1, 2, 6, 7, 9],
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[4, 8, 3, 9, 7, 5, 6, 1, 2],
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[9, 7, 4, 2, 5, 8, 3, 1, 6],
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[2, 6, 4, 9, 8, 7, 5, 1, 3],
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[2, 7, 8, 6, 5, 3, 4, 1, 9],
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[1, 6, 2, 3, 8, 5, 4, 9, 7],
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[5, 6, 9, 1, 2, 8, 4, 3, 7],
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[6, 1, 4, 7, 5, 8, 3, 9, 2]]
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}
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#
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# Data from
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# http://www.csee.wvu.edu/~ksmani/courses/fa01/random/lecnotes/lecture5.pdf
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#
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problem3 = {
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"rankWomen": [
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[1, 2, 3, 4],
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[4, 3, 2, 1],
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[1, 2, 3, 4],
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[3, 4, 1, 2]],
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"rankMen": [
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[1, 2, 3, 4],
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[2, 1, 3, 4],
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[1, 4, 3, 2],
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[4, 3, 1, 2]]
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}
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#
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# Data from
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# http://www.comp.rgu.ac.uk/staff/ha/ZCSP/additional_problems/stable_marriage/stable_marriage.pdf
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# page 4
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#
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problem4 = {
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"rankWomen": [
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[1, 5, 4, 6, 2, 3],
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[4, 1, 5, 2, 6, 3],
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[6, 4, 2, 1, 5, 3],
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[1, 5, 2, 4, 3, 6],
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[4, 2, 1, 5, 6, 3],
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[2, 6, 3, 5, 1, 4]],
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"rankMen": [
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[1, 4, 2, 5, 6, 3],
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[3, 4, 6, 1, 5, 2],
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[1, 6, 4, 2, 3, 5],
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[6, 5, 3, 4, 2, 1],
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[3, 1, 2, 4, 5, 6],
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[2, 3, 1, 6, 5, 4]]
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}
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if __name__ == "__main__":
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main(van_hentenryck, "Van Hentenryck")
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main(mathworld, "MathWorld")
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main(problem3, "Problem 3")
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main(problem4, "Problem4")
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