55 lines
1.8 KiB
Python
55 lines
1.8 KiB
Python
#!/usr/bin/env python
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# This Python file uses the following encoding: utf-8
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# Copyright 2018 Google LLC
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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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"""Constraint optimization example"""
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from __future__ import print_function
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from ortools.constraint_solver import pywrapcp
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def main():
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"""Entry point of the program"""
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solver = pywrapcp.Solver('ConstraintExample')
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# Create the variables.
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num_vals = 3
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x = solver.IntVar(0, num_vals - 1, 'x')
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y = solver.IntVar(0, num_vals - 1, 'y')
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z = solver.IntVar(0, num_vals - 1, 'z')
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# Constraint 0: x != y.
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solver.Add(x != y)
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print('Number of constraints =', solver.Constraints())
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# Call the solver.
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decision_builder = solver.Phase([x, y, z], solver.CHOOSE_FIRST_UNBOUND,
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solver.ASSIGN_MIN_VALUE)
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solver.NewSearch(decision_builder)
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while solver.NextSolution():
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solution = 'Solution:'
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for var in [x, y, z]:
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solution += ' {} = {};'.format(var.Name(), var.Value())
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print(solution)
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solver.EndSearch()
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print("Number of solutions found:", solver.Solutions())
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print('')
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print('Advanced usage:')
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print('Problem solved in ', solver.WallTime(), ' milliseconds')
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print('Memory usage: ', pywrapcp.Solver.MemoryUsage(), ' bytes')
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if __name__ == "__main__":
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main()
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