61 lines
2.0 KiB
C++
61 lines
2.0 KiB
C++
// 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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#ifndef ORTOOLS_SAT_DRAT_WRITER_H_
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#define ORTOOLS_SAT_DRAT_WRITER_H_
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#include <string>
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#include "absl/types/span.h"
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#include "ortools/base/file.h"
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#include "ortools/sat/sat_base.h"
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namespace operations_research {
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namespace sat {
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// DRAT is a SAT proof format that allows a simple program to check that the
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// problem is really UNSAT. The description of the format and a checker are
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// available at: // http://www.cs.utexas.edu/~marijn/drat-trim/
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//
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// Note that DRAT proofs are often huge (can be GB), and take about as much time
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// to check as it takes for the solver to find the proof in the first place!
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class DratWriter {
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public:
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DratWriter(bool in_binary_format, File* output)
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: in_binary_format_(in_binary_format), output_(output) {}
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~DratWriter();
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// Writes a new clause to the DRAT output. Note that the RAT property is only
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// checked on the first literal.
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void AddClause(absl::Span<const Literal> clause);
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// Writes a "deletion" information about a clause that has been added before
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// to the DRAT output. Note that it is also possible to delete a clause from
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// the problem.
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void DeleteClause(absl::Span<const Literal> clause);
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private:
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void WriteClause(absl::Span<const Literal> clause);
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// TODO(user): Support binary format as proof in text format can be large.
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bool in_binary_format_;
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File* output_;
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std::string buffer_;
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};
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} // namespace sat
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} // namespace operations_research
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#endif // ORTOOLS_SAT_DRAT_WRITER_H_
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