math_opt: backport from main

ortools/math_opt/constraints/indicator/BUILD.bazel

@@ -11,6 +11,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+load("@rules_cc//cc:cc_test.bzl", "cc_test")
+
 package(default_visibility = ["//ortools/math_opt:__subpackages__"])
 
 cc_library(

ortools/math_opt/constraints/quadratic/BUILD.bazel

@@ -11,6 +11,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+load("@rules_cc//cc:cc_test.bzl", "cc_test")
+
 package(default_visibility = ["//ortools/math_opt:__subpackages__"])
 
 cc_library(

ortools/math_opt/constraints/second_order_cone/BUILD.bazel

@@ -11,6 +11,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+load("@rules_cc//cc:cc_test.bzl", "cc_test")
+
 package(default_visibility = ["//ortools/math_opt:__subpackages__"])
 
 cc_library(

ortools/math_opt/constraints/sos/BUILD.bazel

@@ -11,6 +11,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+load("@rules_cc//cc:cc_test.bzl", "cc_test")
+
 package(default_visibility = ["//ortools/math_opt:__subpackages__"])
 
 cc_library(

ortools/math_opt/constraints/util/BUILD.bazel

@@ -11,6 +11,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+load("@rules_cc//cc:cc_test.bzl", "cc_test")
+
 package(default_visibility = ["//ortools/math_opt:__subpackages__"])
 
 cc_library(

ortools/math_opt/core/BUILD.bazel

@@ -11,6 +11,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+
 package(default_visibility = ["//ortools/math_opt:__subpackages__"])
 
 cc_library(
@@ -62,9 +64,9 @@ cc_library(
     deps = [
         "//ortools/base:linked_hash_map",
         "//ortools/base:status_macros",
+        "//ortools/base:string_view_migration",
         "//ortools/math_opt:model_cc_proto",
         "//ortools/math_opt:model_update_cc_proto",
-        "//ortools/base:string_view_migration",
         "@abseil-cpp//absl/algorithm:container",
         "@abseil-cpp//absl/container:flat_hash_map",
         "@abseil-cpp//absl/log:check",

ortools/math_opt/cpp/BUILD.bazel

@@ -11,6 +11,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+
 # External users should depend only on ":math_opt" and include
 # "math_opt.h". Hence other libraries are private.
 package(default_visibility = [

ortools/math_opt/elemental/python/BUILD.bazel

@@ -14,7 +14,7 @@
 load("@pip_deps//:requirements.bzl", "requirement")
 load("@pybind11_bazel//:build_defs.bzl", "pybind_extension")
 load("@rules_python//python:py_library.bzl", "py_library")
-load("@rules_python//python:py_test.bzl",  "py_test")
+load("@rules_python//python:py_test.bzl", "py_test")
 
 genrule(
     name = "generated_enums",

ortools/math_opt/python/BUILD.bazel

@@ -13,7 +13,7 @@
 
 load("@pip_deps//:requirements.bzl", "requirement")
 load("@rules_python//python:py_library.bzl", "py_library")
-load("@rules_python//python:py_test.bzl",  "py_test")
+load("@rules_python//python:py_test.bzl", "py_test")
 
 # External users should depend only on ":mathopt" and import "mathopt".
 # Hence other libraries are private.

ortools/math_opt/python/ipc/BUILD.bazel

@@ -12,7 +12,7 @@
 # limitations under the License.
 
 load("@pip_deps//:requirements.bzl", "requirement")
-load("@rules_python//python:defs.bzl", "py_library")
+load("@rules_python//python:py_library.bzl", "py_library")
 
 py_library(
     name = "remote_http_solve",

ortools/math_opt/python/testing/BUILD.bazel

@@ -13,7 +13,7 @@
 
 load("@pip_deps//:requirements.bzl", "requirement")
 load("@rules_python//python:py_library.bzl", "py_library")
-load("@rules_python//python:py_test.bzl",  "py_test")
+load("@rules_python//python:py_test.bzl", "py_test")
 
 package(default_visibility = ["//ortools/math_opt:__subpackages__"])
 

ortools/math_opt/solver_tests/test_models_test.cc

@@ -24,21 +24,25 @@ namespace operations_research::math_opt {
 
 using ::testing::status::IsOkAndHolds;
 
+#if defined(USE_SCIP)
 TEST(SmallModelTest, Integer) {
   const std::unique_ptr<const Model> model = SmallModel(/*integer=*/true);
   EXPECT_THAT(Solve(*model, SolverType::kGscip), IsOkAndHolds(IsOptimal(9.0)));
 }
+#endif  // USE_SCIP
 
 TEST(SmallModelTest, Continuous) {
   const std::unique_ptr<const Model> model = SmallModel(/*integer=*/false);
   EXPECT_THAT(Solve(*model, SolverType::kGlop), IsOkAndHolds(IsOptimal(12.0)));
 }
 
+#if defined(USE_SCIP)
 TEST(DenseIndependentSetTest, Integer) {
   const std::unique_ptr<const Model> model =
       DenseIndependentSet(/*integer=*/true);
   EXPECT_THAT(Solve(*model, SolverType::kGscip), IsOkAndHolds(IsOptimal(7.0)));
 }
+#endif  // USE_SCIP
 
 TEST(DenseIndependentSetTest, Continuous) {
   const std::unique_ptr<const Model> model =
@@ -47,6 +51,7 @@ TEST(DenseIndependentSetTest, Continuous) {
               IsOkAndHolds(IsOptimal(10.0 * (5 + 4 + 3) / 2.0)));
 }
 
+#if defined(USE_SCIP)
 TEST(DenseIndependentSetHint5Test, HintIsFeasibleWithObjective5) {
   const std::unique_ptr<Model> model = DenseIndependentSet(/*integer=*/true, 5);
   ModelSolveParameters model_params;
@@ -58,12 +63,15 @@ TEST(DenseIndependentSetHint5Test, HintIsFeasibleWithObjective5) {
   }
   EXPECT_THAT(Solve(*model, SolverType::kGscip), IsOkAndHolds(IsOptimal(5.0)));
 }
+#endif  // USE_SCIP
 
+#if defined(USE_SCIP)
 TEST(IndependentSetCompleteGraphTest, Integer) {
   const std::unique_ptr<const Model> model =
       IndependentSetCompleteGraph(/*integer=*/true);
   EXPECT_THAT(Solve(*model, SolverType::kGscip), IsOkAndHolds(IsOptimal(1.0)));
 }
+#endif  // USE_SCIP
 
 TEST(IndependentSetCompleteGraphTest, Continuous) {
   const std::unique_ptr<const Model> model =

ortools/math_opt/solvers/highs_solver.cc

@@ -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.

ortools/math_opt/solvers/highs_solver_test.cc

@@ -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);

ortools/math_opt/solvers/xpress/BUILD.bazel

@@ -11,6 +11,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+load("@rules_cc//cc:cc_library.bzl", "cc_library")
+
 # Code specific to XPRESS used in xpress_solver.cc.
 package(default_visibility = ["//ortools/math_opt/solvers:__subpackages__"])