OR-Tools  8.2
cp_model_objective.h
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1// Copyright 2010-2018 Google LLC
2// Licensed under the Apache License, Version 2.0 (the "License");
3// you may not use this file except in compliance with the License.
4// You may obtain a copy of the License at
5//
6// http://www.apache.org/licenses/LICENSE-2.0
7//
8// Unless required by applicable law or agreed to in writing, software
9// distributed under the License is distributed on an "AS IS" BASIS,
10// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11// See the License for the specific language governing permissions and
12// limitations under the License.
13
14#ifndef OR_TOOLS_SAT_CP_MODEL_OBJECTIVE_H_
15#define OR_TOOLS_SAT_CP_MODEL_OBJECTIVE_H_
16
17#include "ortools/sat/cp_model.pb.h"
18
19namespace operations_research {
20namespace sat {
21
22// If the objective contains more than one term, a new integer variable will be
23// created and an equality constraint will be added to the model to force
24// this new variable to be equal to the old linear combinaison defining the
25// objective.
26//
27// If the objective contains only one term, we canonicalize it so that its
28// coefficient is one. If there is no objecitve, this has no effect.
29//
30// The main raison to do that is that the objective can be preprocessed like
31// any linear constraint before beeing "extracted" again.
32//
33// TODO(user): Add only a >= constraint? Not sure it is useful to do that before
34// presolve, we can always do this optimization just before solving the model.
35void EncodeObjectiveAsSingleVariable(CpModelProto* cp_model);
36
37} // namespace sat
38} // namespace operations_research
39
40#endif // OR_TOOLS_SAT_CP_MODEL_OBJECTIVE_H_
void EncodeObjectiveAsSingleVariable(CpModelProto *cp_model)
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