52 lines
1.8 KiB
C++
52 lines
1.8 KiB
C++
// Copyright 2010-2022 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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#include "ortools/algorithms/set_cover_utils.h"
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#include "ortools/base/adjustable_priority_queue-inl.h" // IWYU pragma: keep
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namespace operations_research {
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void SubsetPriorityQueue::Initialize() {
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max_pq_.Clear();
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pq_elements_.assign(ledger_->model()->num_subsets(), SubsetPriority());
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}
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void SubsetPriorityQueue::Add(SubsetIndex subset, Cost priority) {
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pq_elements_[subset] = SubsetPriority(subset, priority);
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max_pq_.Add(&pq_elements_[subset]);
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}
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void SubsetPriorityQueue::ChangePriority(SubsetIndex subset, Cost priority) {
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// TODO(user): see if the reference to ledger_ can be removed.
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if (ledger_->marginal_impacts(subset) != 0) {
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pq_elements_[subset].SetPriority(priority);
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max_pq_.NoteChangedPriority(&pq_elements_[subset]);
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DVLOG(1) << "Priority of subset " << subset << " is now "
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<< pq_elements_[subset].GetPriority();
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}
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}
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void SubsetPriorityQueue::Remove(SubsetIndex subset) {
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if (max_pq_.Contains(&pq_elements_[subset])) {
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DVLOG(1) << "Removing subset " << subset << " from priority queue";
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max_pq_.Remove(&pq_elements_[subset]);
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}
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}
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SubsetIndex SubsetPriorityQueue::TopSubset() const {
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return max_pq_.Top()->GetSubset();
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}
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} // namespace operations_research
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