85 lines
2.8 KiB
C++
85 lines
2.8 KiB
C++
// Copyright 2010-2021 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 <algorithm>
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#include <cstdint>
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#include <iterator>
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#include <numeric>
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#include <sstream>
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#include "ortools/algorithms/knapsack_solver.h"
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// [END import]
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namespace operations_research {
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namespace algorithms {
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void SimpleKnapsackProgram() {
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// [START solver]
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KnapsackSolver solver(KnapsackSolver::KNAPSACK_DYNAMIC_PROGRAMMING_SOLVER,
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"SimpleKnapsackExample");
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// [END solver]
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// [START data]
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std::vector<std::vector<int64_t>> weights = {{565, 406, 194, 130, 435, 367,
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230, 315, 393, 125, 670, 892,
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600, 293, 712, 147, 421, 255}};
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std::vector<int64_t> capacities = {850};
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std::vector<int64_t> values = weights[0];
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// [END data]
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// [START solve]
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solver.Init(values, weights, capacities);
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int64_t computed_value = solver.Solve();
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// [END solve]
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// [START print_solution]
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std::vector<int> packed_items;
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for (std::size_t i = 0; i < values.size(); ++i) {
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if (solver.BestSolutionContains(i)) packed_items.push_back(i);
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}
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std::ostringstream packed_items_ss;
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std::copy(packed_items.begin(), packed_items.end() - 1,
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std::ostream_iterator<int>(packed_items_ss, ", "));
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packed_items_ss << packed_items.back();
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std::vector<int64_t> packed_weights;
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packed_weights.reserve(packed_items.size());
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for (const auto& it : packed_items) {
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packed_weights.push_back(weights[0][it]);
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}
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std::ostringstream packed_weights_ss;
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std::copy(packed_weights.begin(), packed_weights.end() - 1,
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std::ostream_iterator<int>(packed_weights_ss, ", "));
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packed_weights_ss << packed_weights.back();
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int64_t total_weights =
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std::accumulate(packed_weights.begin(), packed_weights.end(), int64_t{0});
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LOG(INFO) << "Total value: " << computed_value;
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LOG(INFO) << "Packed items: {" << packed_items_ss.str() << "}";
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LOG(INFO) << "Total weight: " << total_weights;
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LOG(INFO) << "Packed weights: {" << packed_weights_ss.str() << "}";
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// [END print_solution]
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}
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} // namespace algorithms
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} // namespace operations_research
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int main() {
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operations_research::algorithms::SimpleKnapsackProgram();
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return EXIT_SUCCESS;
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}
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// [END program]
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