c34026b101
note: done using ```sh git grep -l "2010-2024 Google" | xargs sed -i 's/2010-2024 Google/2010-2025 Google/' ```
70 lines
2.6 KiB
C++
70 lines
2.6 KiB
C++
// Copyright 2010-2025 Google LLC
|
|
// 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.
|
|
|
|
#ifndef OR_TOOLS_SAT_RINS_H_
|
|
#define OR_TOOLS_SAT_RINS_H_
|
|
|
|
#include <cstdint>
|
|
#include <string>
|
|
#include <utility>
|
|
#include <vector>
|
|
|
|
#include "absl/random/bit_gen_ref.h"
|
|
#include "ortools/sat/model.h"
|
|
#include "ortools/sat/synchronization.h"
|
|
|
|
namespace operations_research {
|
|
namespace sat {
|
|
|
|
// A RINS Neighborhood is actually just a generic neighborhood where the domain
|
|
// of some variable have been reduced (fixed or restricted in [lb, ub]).
|
|
//
|
|
// Important: It might be possible that the value of the variables here are
|
|
// outside the domains of these variables! This happens for RENS type of
|
|
// neighborhood in the presence of holes in the domains because the LP
|
|
// relaxation ignore those.
|
|
struct ReducedDomainNeighborhood {
|
|
// A variable will appear only once and not in both vectors.
|
|
std::vector<std::pair</*model_var*/ int, /*value*/ int64_t>> fixed_vars;
|
|
std::vector<
|
|
std::pair</*model_var*/ int, /*domain*/ std::pair<int64_t, int64_t>>>
|
|
reduced_domain_vars;
|
|
std::string source_info;
|
|
};
|
|
|
|
// Helper method to create a RINS neighborhood by fixing variables with same
|
|
// values in relaxation solution and the current best solution in the
|
|
// response_manager. Prioritizes repositories in following order to get a
|
|
// neighborhood.
|
|
// 1. incomplete_solutions
|
|
// 2. lp_solutions
|
|
//
|
|
// If response_manager has no solution, this generates a RENS neighborhood by
|
|
// ignoring the solutions and using the relaxation values. The domain of the
|
|
// variables are reduced to integer values around relaxation values. If the
|
|
// relaxation value is integer, then we fix the domain of the variable to that
|
|
// value.
|
|
ReducedDomainNeighborhood GetRinsRensNeighborhood(
|
|
const SharedResponseManager* response_manager,
|
|
const SharedLPSolutionRepository* lp_solutions,
|
|
SharedIncompleteSolutionManager* incomplete_solutions, double difficulty,
|
|
absl::BitGenRef random);
|
|
|
|
// Adds the current LP solution to the pool.
|
|
void RecordLPRelaxationValues(Model* model);
|
|
|
|
} // namespace sat
|
|
} // namespace operations_research
|
|
|
|
#endif // OR_TOOLS_SAT_RINS_H_
|