59 lines
2.0 KiB
C++
59 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_MATH_OPT_ELEMENTAL_ATTR_DIFF_H_
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#define ORTOOLS_MATH_OPT_ELEMENTAL_ATTR_DIFF_H_
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#include <cstdint>
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#include <utility>
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#include "absl/container/flat_hash_set.h"
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#include "ortools/math_opt/elemental/attr_key.h"
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namespace operations_research::math_opt {
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// Tracks modifications to an Attribute with a key size of n (e.g., variable
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// lower bound has a key size of 1).
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template <int n, typename Symmetry>
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class AttrDiff {
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public:
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using Key = AttrKey<n, Symmetry>;
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// On creation, the attribute is not modified for any key.
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AttrDiff() = default;
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// Clear all tracked modifications.
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void Advance() { modified_keys_.clear(); }
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// Mark the attribute as modified for `key`.
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void SetModified(const Key key) { modified_keys_.insert(key); }
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// Returns the attribute keys that have been modified for this attribute (the
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// elements where set_modified() was called without a subsequent call to
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// Advance()).
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const AttrKeyHashSet<Key>& modified_keys() const { return modified_keys_; }
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bool has_modified_keys() const { return !modified_keys_.empty(); }
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// Stop tracking modifications for this attribute key. (Typically invoked when
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// an element in the key was deleted from the model.)
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void Erase(const Key key) { modified_keys_.erase(key); }
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private:
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AttrKeyHashSet<Key> modified_keys_;
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};
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} // namespace operations_research::math_opt
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#endif // ORTOOLS_MATH_OPT_ELEMENTAL_ATTR_DIFF_H_
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