90 lines
2.6 KiB
C++
90 lines
2.6 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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// [START program]
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// [START import]
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#include "ortools/graph/assignment.h"
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#include <cstdlib>
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#include <numeric>
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#include <string>
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#include <vector>
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#include "absl/base/log_severity.h"
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#include "absl/log/globals.h"
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#include "absl/log/log.h"
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#include "ortools/base/init_google.h"
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// [END import]
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namespace operations_research {
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// Simple Linear Sum Assignment Problem (LSAP).
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void AssignmentLinearSumAssignment() {
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// [START solver]
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SimpleLinearSumAssignment assignment;
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// [END solver]
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// [START data]
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const int num_workers = 4;
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std::vector<int> all_workers(num_workers);
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std::iota(all_workers.begin(), all_workers.end(), 0);
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const int num_tasks = 4;
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std::vector<int> all_tasks(num_tasks);
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std::iota(all_tasks.begin(), all_tasks.end(), 0);
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const std::vector<std::vector<int>> costs = {{
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{{90, 76, 75, 70}}, // Worker 0
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{{35, 85, 55, 65}}, // Worker 1
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{{125, 95, 90, 105}}, // Worker 2
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{{45, 110, 95, 115}}, // Worker 3
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}};
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// [END data]
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// [START constraints]
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for (int w : all_workers) {
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for (int t : all_tasks) {
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if (costs[w][t]) {
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assignment.AddArcWithCost(w, t, costs[w][t]);
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}
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}
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}
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// [END constraints]
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// [START solve]
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SimpleLinearSumAssignment::Status status = assignment.Solve();
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// [END solve]
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// [START print_solution]
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if (status == SimpleLinearSumAssignment::OPTIMAL) {
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LOG(INFO) << "Total cost: " << assignment.OptimalCost();
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for (int worker : all_workers) {
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LOG(INFO) << "Worker " << std::to_string(worker) << " assigned to task "
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<< std::to_string(assignment.RightMate(worker)) << ". Cost: "
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<< std::to_string(assignment.AssignmentCost(worker)) << ".";
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}
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} else {
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LOG(INFO) << "Solving the linear assignment problem failed.";
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}
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// [END print_solution]
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}
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} // namespace operations_research
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int main(int argc, char* argv[]) {
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InitGoogle(argv[0], &argc, &argv, true);
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absl::SetStderrThreshold(absl::LogSeverityAtLeast::kInfo);
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operations_research::AssignmentLinearSumAssignment();
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return EXIT_SUCCESS;
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}
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// [END program]
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