[CP-SAT] add hinting API for literals + test

google · Aug 13, 2024 · de27013 · de27013
1 parent 1d4c84f
commit de27013
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diff --git a/ortools/sat/csharp/CpModel.cs b/ortools/sat/csharp/CpModel.cs
@@ -1042,6 +1042,23 @@ public void AddHint(IntVar var, long value)
         model_.SolutionHint.Values.Add(value);
     }
 
+    /** <summary>Adds variable hinting to the model.</summary>*/
+    public void AddHint(ILiteral lit, bool value)
+    {
+        model_.SolutionHint ??= new PartialVariableAssignment();
+        int index = lit.GetIndex();
+        if (index >= 0)
+        {
+            model_.SolutionHint.Vars.Add(index);
+            model_.SolutionHint.Values.Add(value ? 1 : 0);
+        }
+        else
+        {
+            model_.SolutionHint.Vars.Add(Negated(index));
+            model_.SolutionHint.Values.Add(value ? 0 : 1);
+        }
+    }    
+
     /** <summary>Clears all hinting from the model.</summary>*/
     public void ClearHints()
     {

diff --git a/ortools/sat/csharp/SatSolverTests.cs b/ortools/sat/csharp/SatSolverTests.cs
@@ -752,5 +752,25 @@ public void TestInterval()
         Assert.Equal("3", i.SizeExpr().ToString());
         Assert.Equal("(v + 3)", i.EndExpr().ToString());
     }
+
+    [Fact]
+    public void TestHint()
+    {
+        output_.WriteLine("TestInterval test");
+        CpModel model = new CpModel();
+        IntVar v = model.NewIntVar(-10, 10, "v");
+        BoolVar b = model.NewBoolVar("b");
+        BoolVar c = model.NewBoolVar("c");
+        model.AddHint(v, 3);
+        model.AddHint(b, false);
+        model.AddHint(c.Not(), false);
+        Assert.Equal(3, model.Model.SolutionHint.Vars.Count);
+        Assert.Equal(0, model.Model.SolutionHint.Vars[0]);
+        Assert.Equal(3, model.Model.SolutionHint.Values[0]);
+        Assert.Equal(1, model.Model.SolutionHint.Vars[1]);
+        Assert.Equal(0, model.Model.SolutionHint.Values[1]);
+        Assert.Equal(2, model.Model.SolutionHint.Vars[2]);
+        Assert.Equal(1, model.Model.SolutionHint.Values[2]);
+    }    
 }
 } // namespace Google.OrTools.Tests