always-cautious/ortools-clone
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

fix example

Browse Source
This commit is contained in:
Laurent Perron
2020-06-24 19:04:13 +02:00
parent b4408f9f10
commit 86057e169b
1 changed files with 29 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files

66
examples/cpp/integer_programming.cc
View File

@@ -17,37 +17,42 @@
#include "ortools/linear_solver/linear_solver.h"
namespace operations_research {
void RunIntegerProgrammingExample(
MPSolver::OptimizationProblemType optimization_problem_type) {
MPSolver solver("IntegerProgrammingExample", optimization_problem_type);
const double infinity = solver.infinity();
void RunIntegerProgrammingExample(const std::string& optimization_problem_type) {
LOG(INFO) << "---- Integer programming example with "
<< optimization_problem_type << " ----";
std::unique_ptr<MPSolver> solver(MPSolver::CreateSolver(
"IntegerProgrammingExample", optimization_problem_type));
if (solver.get() == nullptr) return;
const double infinity = solver->infinity();
// x and y are integer non-negative variables.
MPVariable* const x = solver.MakeIntVar(0.0, infinity, "x");
MPVariable* const y = solver.MakeIntVar(0.0, infinity, "y");
MPVariable* const x = solver->MakeIntVar(0.0, infinity, "x");
MPVariable* const y = solver->MakeIntVar(0.0, infinity, "y");
// Maximize x + 10 * y.
MPObjective* const objective = solver.MutableObjective();
MPObjective* const objective = solver->MutableObjective();
objective->SetCoefficient(x, 1);
objective->SetCoefficient(y, 10);
objective->SetMaximization();
// x + 7 * y <= 17.5.
MPConstraint* const c0 = solver.MakeRowConstraint(-infinity, 17.5);
MPConstraint* const c0 = solver->MakeRowConstraint(-infinity, 17.5);
c0->SetCoefficient(x, 1);
c0->SetCoefficient(y, 7);
// x <= 3.5
MPConstraint* const c1 = solver.MakeRowConstraint(-infinity, 3.5);
MPConstraint* const c1 = solver->MakeRowConstraint(-infinity, 3.5);
c1->SetCoefficient(x, 1);
c1->SetCoefficient(y, 0);
LOG(INFO) << "Number of variables = " << solver.NumVariables();
LOG(INFO) << "Number of constraints = " << solver.NumConstraints();
LOG(INFO) << "Number of variables = " << solver->NumVariables();
LOG(INFO) << "Number of constraints = " << solver->NumConstraints();
solver.SetNumThreads(8);
solver.EnableOutput();
solver->SetNumThreads(8);
solver->EnableOutput();
const MPSolver::ResultStatus result_status = solver.Solve();
const MPSolver::ResultStatus result_status = solver->Solve();
// Check that the problem has an optimal solution.
if (result_status != MPSolver::OPTIMAL) {
LOG(FATAL) << "The problem does not have an optimal solution!";
@@ -58,34 +63,21 @@ void RunIntegerProgrammingExample(
LOG(INFO) << "Optimal objective value = " << objective->Value();
LOG(INFO) << "";
LOG(INFO) << "Advanced usage:";
LOG(INFO) << "Problem solved in " << solver.wall_time() << " milliseconds";
LOG(INFO) << "Problem solved in " << solver.iterations() << " iterations";
LOG(INFO) << "Problem solved in " << solver.nodes()
LOG(INFO) << "Problem solved in " << solver->wall_time() << " milliseconds";
LOG(INFO) << "Problem solved in " << solver->iterations() << " iterations";
LOG(INFO) << "Problem solved in " << solver->nodes()
<< " branch-and-bound nodes";
}
void RunAllExamples() {
#if defined(USE_CBC)
LOG(INFO) << "---- Integer programming example with CBC ----";
RunIntegerProgrammingExample(MPSolver::CBC_MIXED_INTEGER_PROGRAMMING);
#endif
#if defined(USE_GLPK)
LOG(INFO) << "---- Integer programming example with GLPK ----";
RunIntegerProgrammingExample(MPSolver::GLPK_MIXED_INTEGER_PROGRAMMING);
#endif
#if defined(USE_SCIP)
LOG(INFO) << "---- Integer programming example with SCIP ----";
RunIntegerProgrammingExample(MPSolver::SCIP_MIXED_INTEGER_PROGRAMMING);
#endif
#if defined(USE_GUROBI)
LOG(INFO) << "---- Integer programming example with Gurobi ----";
RunIntegerProgrammingExample(MPSolver::GUROBI_MIXED_INTEGER_PROGRAMMING);
#endif // USE_GUROBI
#if defined(USE_CPLEX)
LOG(INFO) << "---- Integer programming example with CPLEX ----";
RunIntegerProgrammingExample(MPSolver::CPLEX_MIXED_INTEGER_PROGRAMMING);
#endif // USE_CPLEX
RunIntegerProgrammingExample("CBC");
RunIntegerProgrammingExample("SAT");
RunIntegerProgrammingExample("SCIP");
RunIntegerProgrammingExample("GUROBI");
RunIntegerProgrammingExample("GLPK");
RunIntegerProgrammingExample("CPLEX");
}
} // namespace operations_research
int main(int argc, char** argv) {