70 lines
1.9 KiB
Python
70 lines
1.9 KiB
Python
#!/usr/bin/env python3
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# Copyright 2010-2025 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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"""Code sample that solves a model and gets the infeasibility assumptions."""
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# [START program]
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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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"""Showcases assumptions."""
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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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x = model.new_int_var(0, 10, "x")
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y = model.new_int_var(0, 10, "y")
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z = model.new_int_var(0, 10, "z")
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a = model.new_bool_var("a")
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b = model.new_bool_var("b")
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c = model.new_bool_var("c")
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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(x > y).only_enforce_if(a)
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model.add(y > z).only_enforce_if(b)
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model.add(z > x).only_enforce_if(c)
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# [END constraints]
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# Add assumptions
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model.add_assumptions([a, b, c])
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# Creates a solver and solves.
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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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# Print solution.
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# [START print_solution]
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print(f"Status = {solver.status_name(status)}")
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if status == cp_model.INFEASIBLE:
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print(
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"sufficient_assumptions_for_infeasibility = "
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f"{solver.sufficient_assumptions_for_infeasibility()}"
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)
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# [END print_solution]
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if __name__ == "__main__":
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main()
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# [END program]
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