027f5cc3f8
C++: - [Up] linear_programming - [Up] integer_programming - constraint_programming_CP / rabbits_pheasants_cp - knapsack - max_flow / min_cost_flow - tsp / vrp note: previous "fuzzy" tsp has been renamed random_tsp. .Net: - vrp
81 lines
2.8 KiB
C++
81 lines
2.8 KiB
C++
// Copyright 2018 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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// Bi-dimensional knapsack problem.
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#include <numeric>
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#include <sstream>
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#include <iterator>
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#include "ortools/base/logging.h"
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#include "ortools/algorithms/knapsack_solver.h"
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namespace operations_research {
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void RunKnapsackExample() {
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// Instantiate the solver.
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KnapsackSolver solver(
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KnapsackSolver::KNAPSACK_MULTIDIMENSION_BRANCH_AND_BOUND_SOLVER,
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"KnapsackExample");
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std::vector<int64> values = {
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360, 83, 59, 130, 431, 67, 230, 52, 93, 125, 670, 892, 600, 38, 48, 147,
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78, 256, 63, 17, 120, 164, 432, 35, 92, 110, 22, 42, 50, 323, 514, 28, 87,
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73, 78, 15, 26, 78, 210, 36, 85, 189, 274, 43, 33, 10, 19, 389, 276, 312
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};
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std::vector<std::vector<int64>> weights = {
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{
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7, 0, 30, 22, 80, 94, 11, 81, 70, 64, 59, 18, 0, 36, 3, 8, 15, 42, 9, 0,
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42, 47, 52, 32, 26, 48, 55, 6, 29, 84, 2, 4, 18, 56, 7, 29, 93, 44, 71, 3,
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86, 66, 31, 65, 0, 79, 20, 65, 52, 13
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}
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};
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std::vector<int64> capacities = {850};
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solver.Init(values, weights, capacities);
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int64 computed_value = solver.Solve();
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// 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, std::ostream_iterator<int>(packed_items_ss, ", "));
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packed_items_ss << packed_items.back();
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std::vector<int64> 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, std::ostream_iterator<int>(packed_weights_ss, ", "));
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packed_weights_ss << packed_weights.back();
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int64 total_weights = std::accumulate(packed_weights.begin(), packed_weights.end(), 0LL);
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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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}
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} // namespace operations_research
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int main(int argc, char **argv) {
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google::InitGoogleLogging(argv[0]);
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FLAGS_logtostderr = 1;
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operations_research::RunKnapsackExample();
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return 0;
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}
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