60 lines
1.8 KiB
Python
60 lines
1.8 KiB
Python
# Copyright 2010-2017 Google
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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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"""Rabbit + Pheasant puzzle.
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This example is the same one described in
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util/constraint/constraint_solver/constraint_solver.h
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rewritten using the SWIG generated python wrapper.
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Its purpose it to demonstrate how a simple example can be written in all the
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flavors of constraint programming interfaces.
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"""
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from __future__ import print_function
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from ortools.constraint_solver import pywrapcp
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from ortools.constraint_solver import solver_parameters_pb2
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def main():
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parameters = pywrapcp.Solver.DefaultSolverParameters()
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parameters.trace_search = True
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# Create the solver.
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solver = pywrapcp.Solver('rabbit+pheasant', parameters)
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# Create the variables.
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pheasant = solver.IntVar(0, 100, 'pheasant')
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rabbit = solver.IntVar(0, 100, 'rabbit')
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# Create the constraints.
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solver.Add(pheasant + rabbit == 20)
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solver.Add(pheasant * 2 + rabbit * 4 == 56)
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# Create the search phase.
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db = solver.Phase([rabbit, pheasant],
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solver.INT_VAR_DEFAULT,
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solver.INT_VALUE_DEFAULT)
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# And solve.
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solver.NewSearch(db)
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solver.NextSolution()
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# Display output.
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print(pheasant)
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print(rabbit)
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solver.EndSearch()
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print(solver)
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if __name__ == '__main__':
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main()
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