75 lines
2.1 KiB
Python
Executable File
75 lines
2.1 KiB
Python
Executable File
#!/usr/bin/env python3
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# Copyright 2010-2022 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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# [START program]
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"""Simple Constraint optimization example."""
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# [START import]
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from ortools.constraint_solver import pywrapcp
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# [END import]
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def main():
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"""Entry point of the program."""
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# Instantiate the solver.
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# [START solver]
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solver = pywrapcp.Solver("CPSimple")
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# [END solver]
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# Create the variables.
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# [START 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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# [END variables]
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# Constraint 0: x != y.
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# [START constraints]
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solver.Add(x != y)
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print("Number of constraints: ", solver.Constraints())
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# [END constraints]
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# Solve the problem.
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# [START solve]
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decision_builder = solver.Phase(
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[x, y, z], solver.CHOOSE_FIRST_UNBOUND, solver.ASSIGN_MIN_VALUE
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)
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# [END solve]
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# Print solution on console.
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# [START print_solution]
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count = 0
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solver.NewSearch(decision_builder)
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while solver.NextSolution():
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count += 1
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solution = f"Solution {count}:\n"
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for var in [x, y, z]:
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solution += f" {var.Name()} = {var.Value()}"
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print(solution)
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solver.EndSearch()
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print(f"Number of solutions found: {count}")
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# [END print_solution]
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# [START advanced]
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print("Advanced usage:")
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print(f"Problem solved in {solver.WallTime()}ms")
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print(f"Memory usage: {pywrapcp.Solver.MemoryUsage()}bytes")
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# [END advanced]
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if __name__ == "__main__":
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main()
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# [END program]
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