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ortools-clone/ortools/sat/samples/reified_sample.cc

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// Copyright 2010-2017 Google
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "ortools/sat/cp_model.pb.h"
#include "ortools/sat/cp_model_solver.h"
#include "ortools/sat/cp_model_utils.h"
#include "ortools/sat/model.h"
namespace operations_research {
namespace sat {
void ReifiedSample() {
CpModelProto cp_model;
auto new_boolean_variable = [&cp_model]() {
const int index = cp_model.variables_size();
IntegerVariableProto* const var = cp_model.add_variables();
var->add_domain(0);
var->add_domain(1);
return index;
};
auto add_bool_or = [&cp_model](const std::vector<int>& literals) {
BoolArgumentProto* const bool_or =
cp_model.add_constraints()->mutable_bool_or();
for (const int lit : literals) {
bool_or->add_literals(lit);
}
};
auto add_reified_bool_and = [&cp_model](const std::vector<int>& literals,
const int literal) {
ConstraintProto* const ct = cp_model.add_constraints();
ct->add_enforcement_literal(literal);
for (const int lit : literals) {
ct->mutable_bool_and()->add_literals(lit);
}
};
const int x = new_boolean_variable();
const int y = new_boolean_variable();
const int b = new_boolean_variable();
// First version using a half-reified bool and.
add_reified_bool_and({x, NegatedRef(y)}, b);
// Second version using bool or.
add_bool_or({NegatedRef(b), x});
add_bool_or({NegatedRef(b), NegatedRef(y)});
}
} // namespace sat
} // namespace operations_research
int main() {
operations_research::sat::ReifiedSample();
return EXIT_SUCCESS;
}