53 lines
1.8 KiB
C++
53 lines
1.8 KiB
C++
#include <ortools/linear_solver/linear_solver.h>
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#include <ortools/linear_solver/linear_solver.pb.h>
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#include <iostream>
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namespace operations_research {
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void RunLinearExample(
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MPSolver::OptimizationProblemType optimization_problem_type) {
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MPSolver solver("LinearExample", optimization_problem_type);
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const double infinity = solver.infinity();
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// x and y are non-negative variables.
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MPVariable* const x = solver.MakeNumVar(0.0, infinity, "x");
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MPVariable* const y = solver.MakeNumVar(0.0, infinity, "y");
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// Objective function: 3x + 4y.
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MPObjective* const objective = solver.MutableObjective();
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objective->SetCoefficient(x, 3);
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objective->SetCoefficient(y, 4);
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objective->SetMaximization();
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// x + 2y <= 14.
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MPConstraint* const c0 = solver.MakeRowConstraint(-infinity, 14.0);
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c0->SetCoefficient(x, 1);
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c0->SetCoefficient(y, 2);
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// 3x - y >= 0.
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MPConstraint* const c1 = solver.MakeRowConstraint(0.0, infinity);
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c1->SetCoefficient(x, 3);
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c1->SetCoefficient(y, -1);
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// x - y <= 2.
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MPConstraint* const c2 = solver.MakeRowConstraint(-infinity, 2.0);
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c2->SetCoefficient(x, 1);
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c2->SetCoefficient(y, -1);
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std::cout << "Number of variables = " << solver.NumVariables() << std::endl;
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std::cout << "Number of constraints = " << solver.NumConstraints()
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<< std::endl;
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solver.Solve();
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// The value of each variable in the solution.
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std::cout << "Solution:" << std::endl
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<< "x = " << x->solution_value() << std::endl
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<< "y = " << y->solution_value() << std::endl;
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// The objective value of the solution.
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std::cout << "Optimal objective value = " << objective->Value() << std::endl;
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}
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void RunExample() { RunLinearExample(MPSolver::GLOP_LINEAR_PROGRAMMING); }
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} // namespace operations_research
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int main(int argc, char** argv) {
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operations_research::RunExample();
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return 0;
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}
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