Merge pull request #4417 from galabovaa/ig-lp-highs

HiGHS updates

Dependencies.txt

@@ -9,7 +9,7 @@ Clp=1.17.7
 Cgl=0.60.5
 Cbc=2.10.7
 GLPK=5.0
-HiGHS=v1.7.2
+HiGHS=v1.8.0
 Scip=v900
 # Python
 pybind11=v2.12.0

WORKSPACE

@@ -209,7 +209,7 @@ cc_library(
 
 git_repository(
     name = "highs",
-    branch = "v1.7.2",
+    branch = "v1.8.0",
     remote = "https://github.com/ERGO-Code/HiGHS.git",
 )
 

cmake/dependencies/CMakeLists.txt

@@ -249,10 +249,10 @@ if(BUILD_HIGHS)
   FetchContent_Declare(
     highs
     GIT_REPOSITORY "https://github.com/ERGO-Code/HiGHS.git"
-    GIT_TAG        "v1.7.2"
+    GIT_TAG        "v1.8.0"
     GIT_SHALLOW TRUE
     PATCH_COMMAND git apply --ignore-whitespace
-    "${CMAKE_CURRENT_LIST_DIR}/../../patches/highs-v1.7.2.patch"
+    "${CMAKE_CURRENT_LIST_DIR}/../../patches/highs-v1.8.0.patch"
   )
   FetchContent_MakeAvailable(highs)
   list(POP_BACK CMAKE_MESSAGE_INDENT)

examples/cpp/linear_programming.cc

@@ -117,6 +117,7 @@ void RunAllExamples() {
   RunLinearProgrammingExample("GLPK_LP");
   RunLinearProgrammingExample("XPRESS_LP");
   RunLinearProgrammingExample("PDLP");
+  RunLinearProgrammingExample("HIGHS");
 }
 }  // namespace operations_research
 

ortools/linear_solver/proto_solver/highs_proto_solver.cc

@@ -52,7 +52,11 @@ absl::StatusOr<MPSolutionResponse> HighsSolveProto(
   const MPModelProto& model = **optional_model;
 
   Highs highs;
-  // TODO(user): Set model name.
+  // Set model name.
+  if (model.has_name()) {
+    const std::string model_name = model.name();
+    highs.passModelName(model_name);
+  }
 
   if (request->has_solver_specific_parameters()) {
     const auto parameters_status = SetSolverSpecificParameters(
@@ -111,8 +115,29 @@ absl::StatusOr<MPSolutionResponse> HighsSolveProto(
       highs.changeColCost(column, obj_coeffs[column]);
     }
 
-    // TODO(user): Support variable names.
-    // TODO(user): Support hints.
+    // Variable names.
+    for (int v = 0; v < variable_size; ++v) {
+      const MPVariableProto& variable = model.variable(v);
+      std::string varname_str = "";
+      if (!variable.name().empty()) {
+        varname_str = variable.name().c_str();
+        highs.passColName(v, varname_str);
+      }
+    }
+
+    // Hints.
+    int num_hints = model.solution_hint().var_index_size();
+    if (num_hints > 0) {
+      std::vector<HighsInt> hint_index(0, num_hints);
+      std::vector<double> hint_value(0, num_hints);
+      for (int i = 0; i < num_hints; ++i) {
+        hint_index[i] = model.solution_hint().var_index(i);
+        hint_value[i] = model.solution_hint().var_value(i);
+      }
+      const int* hint_indices = &hint_index[0];
+      const double* hint_values = &hint_value[0];
+      highs.setSolution((HighsInt)num_hints, hint_indices, hint_values);
+    }
   }
 
   {
@@ -157,7 +182,16 @@ absl::StatusOr<MPSolutionResponse> HighsSolveProto(
           return response;
         }
       }
-      // TODO(user): Support constraint names.
+
+      // Constraint names.
+      for (int c = 0; c < model.constraint_size(); ++c) {
+        const MPConstraintProto& constraint = model.constraint(c);
+        std::string constraint_name_str = "";
+        if (!constraint.name().empty()) {
+          constraint_name_str = constraint.name().c_str();
+          highs.passRowName(c, constraint_name_str);
+        }
+      }
     }
 
     if (!model.general_constraint().empty()) {
@@ -220,6 +254,9 @@ absl::StatusOr<MPSolutionResponse> HighsSolveProto(
           break;
         default: {
           // TODO(user): report feasible status.
+          const HighsInfo& info = highs.getInfo();
+          if (info.primal_solution_status == kSolutionStatusFeasible)
+            response.set_status(MPSOLVER_FEASIBLE);
           break;
         }
       }

ortools/math_opt/solver_tests/status_tests.cc

@@ -100,7 +100,7 @@ TEST_P(StatusTest, PrimalAndDualInfeasible) {
            "with a primal-dual infeasible LP relaxation.";
   }
   if (GetParam().solver_type == SolverType::kHighs) {
-    GTEST_SKIP() << "Ignoring this test as Highs 1.7+ returns error.";
+    TEST_SKIP() << "Ignoring this test as Highs 1.7+ returns error.";
   }
 
   Model model;