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Merge pull request #4737 from pavlomuts/highs_solution_hint

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Pass solution hint to HiGHS from mathopt
This commit is contained in:
Laurent Perron
2025-07-29 05:44:53 -07:00
committed by GitHub
parent 13e2a14ab6 fd1443e820
commit a3fc2000e4
2 changed files with 28 additions and 5 deletions
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16
ortools/math_opt/solvers/highs_solver.cc
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@@ -14,7 +14,6 @@
// Unimplemented features:
// * Quadratic objective
// * TODO(b/272767311): initial basis, more precise returned basis.
// * Starting solution
// * TODO(b/271104776): Returning rays
#include "ortools/math_opt/solvers/highs_solver.h"
@@ -925,6 +924,21 @@ absl::StatusOr<SolveResultProto> HighsSolver::Solve(
return absl::OkStatus();
};
if (model_parameters.solution_hints_size() > 0) {
// Take the first solution hint and set the solution.
const SolutionHintProto& hint = model_parameters.solution_hints(0);
HighsInt num_entries = hint.variable_values().ids_size();
std::vector<HighsInt> index(num_entries);
std::vector<double> value(num_entries);
size_t i = 0;
for (const auto [id, val] : MakeView(hint.variable_values())) {
index[i] = variable_data_.at(id).index;
value[i] = val;
++i;
}
RETURN_IF_ERROR(ToStatus(highs_->setSolution(num_entries, index.data(), value.data())));
}
RETURN_IF_ERROR(ListInvertedBounds().ToStatus());
// TODO(b/271595607): delete this code once we upgrade HiGHS, if HiGHS does
// return a proper infeasibility status for models with empty integer bounds.

17
ortools/math_opt/solvers/highs_solver_test.cc
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@@ -162,11 +162,20 @@ INSTANTIATE_TEST_SUITE_P(HighsLpModelSolveParametersTest,
Values(LpModelSolveParametersTestParameters(
SolverType::kHighs, /*exact_zeros=*/true,
/*supports_duals=*/true,
/*supports_primal_only_warm_starts=*/false)));
/*supports_primal_only_warm_starts=*/true)));
// MIP hint appears to be supported by Highs::setSolution, this is not yet
// implemented.
GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(MipSolutionHintTest);
SolutionHintTestParams MakeHighsSolutionHintParams() {
SolveParameters solve_params;
solve_params.presolve = Emphasis::kOff;
(*solve_params.highs.mutable_int_options())["mip_max_nodes"] = 0;
std::string hint_message_regex =
"Attempting to find feasible solution by "
"solving MIP for user-supplied values of";
return SolutionHintTestParams(SolverType::kHighs, solve_params, std::nullopt,
hint_message_regex);
}
INSTANTIATE_TEST_SUITE_P(HighsSolutionHintTest, MipSolutionHintTest,
Values(MakeHighsSolutionHintParams()));
// HiGHS does not support branching priority.
GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(BranchPrioritiesTest);