77 lines
2.3 KiB
Python
Executable File
77 lines
2.3 KiB
Python
Executable File
#!/usr/bin/env python3
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# Copyright 2010-2024 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 solve."""
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# [START import]
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from ortools.sat.python import cp_model
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# [END import]
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def main() -> None:
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"""Minimal CP-SAT example to showcase calling the solver."""
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# Creates the model.
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# [START model]
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model = cp_model.CpModel()
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# [END model]
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# Creates the variables.
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# [START variables]
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var_upper_bound = max(50, 45, 37)
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x = model.new_int_var(0, var_upper_bound, "x")
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y = model.new_int_var(0, var_upper_bound, "y")
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z = model.new_int_var(0, var_upper_bound, "z")
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# [END variables]
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# Creates the constraints.
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# [START constraints]
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model.add(2 * x + 7 * y + 3 * z <= 50)
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model.add(3 * x - 5 * y + 7 * z <= 45)
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model.add(5 * x + 2 * y - 6 * z <= 37)
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# [END constraints]
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# [START objective]
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model.maximize(2 * x + 2 * y + 3 * z)
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# [END objective]
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# Creates a solver and solves the model.
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# [START solve]
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solver = cp_model.CpSolver()
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status = solver.solve(model)
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# [END solve]
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# [START print_solution]
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if status == cp_model.OPTIMAL or status == cp_model.FEASIBLE:
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print(f"Maximum of objective function: {solver.objective_value}\n")
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print(f"x = {solver.value(x)}")
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print(f"y = {solver.value(y)}")
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print(f"z = {solver.value(z)}")
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else:
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print("No solution found.")
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# [END print_solution]
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# Statistics.
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# [START statistics]
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print("\nStatistics")
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print(f" status : {solver.status_name(status)}")
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print(f" conflicts: {solver.num_conflicts}")
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print(f" branches : {solver.num_branches}")
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print(f" wall time: {solver.wall_time} s")
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# [END statistics]
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if __name__ == "__main__":
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main()
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# [END program]
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