[ModelBuilder] Add clear_terms and set_coefficient everywhere; finish…

… indicator constraints in C#

ortools/java/com/google/ortools/modelbuilder/EnforcedLinearConstraint.java

@@ -21,6 +21,10 @@ public EnforcedLinearConstraint(ModelBuilderHelper helper) {
   }
 
   EnforcedLinearConstraint(ModelBuilderHelper helper, int index) {
+    if (!helper.isEnforcedConstraint(index)) {
+      throw new IllegalArgumentException(
+          "the given index does not refer to an enforced linear constraint");
+    }
     this.helper = helper;
     this.index = index;
   }
@@ -65,27 +69,37 @@ public void setName(String name) {
     helper.setEnforcedConstraintName(index, name);
   }
 
-  // Adds var * coeff to the constraint.
-  public void addEnforcedTerm(Variable v, double coeff) {
+  /** Adds var * coeff to the constraint.*/
+  public void addTerm(Variable v, double coeff) {
     helper.safeAddEnforcedConstraintTerm(index, v.getIndex(), coeff);
   }
 
-  // Returns the indicator variable of the constraint.
+  /** Sets the coefficient of v to coeff, adding or removing a term if needed. */
+  public void setCoefficient(Variable v, double coeff) {
+    helper.setEnforcedConstraintCoefficient(index, v.getIndex(), coeff);
+  }
+
+  /** Clear all terms. */
+  public void clearTerms() {
+    helper.clearEnforcedConstraintTerms(index);
+  }
+
+  /** Returns the indicator variable of the constraint/ */
   public Variable getIndicatorVariable() {
     return new Variable(helper, helper.getEnforcedIndicatorVariableIndex(index));
   }
 
-  // Sets the indicator variable of the constraint.
+  /** Sets the indicator variable of the constraint. */
   public void setIndicatorVariable(Variable v) {
-    helper.setEnforcedIndicatorVariable(index, v.index);
+    helper.setEnforcedIndicatorVariableIndex(index, v.index);
   }
 
-  // Returns the indicator value of the constraint.
+  /** Returns the indicator value of the constraint. */
   public boolean getIndicatorValue() {
     return helper.getEnforcedIndicatorValue(index);
   }
 
-  // Sets the indicator value of the constraint.
+  /** Sets the indicator value of the constraint. */
   public void setIndicatorValue(boolean b) {
     helper.setEnforcedIndicatorValue(index, b);
   }  

ortools/java/com/google/ortools/modelbuilder/LinearConstraint.java

@@ -60,16 +60,26 @@ public String getName() {
     return helper.getConstraintName(index);
   }
 
-  // Sets the name of the constraint. */
+  /** Sets the name of the constraint. */
   public void setName(String name) {
     helper.setConstraintName(index, name);
   }
 
-  // Adds var * coeff to the constraint.
+  /** Adds var * coeff to the constraint. */
   public void addTerm(Variable v, double coeff) {
     helper.addConstraintTerm(index, v.getIndex(), coeff);
   }
 
+  /** Sets the coefficient of v to coeff, adding or removing a term if needed. */
+  public void setCoefficient(Variable v, double coeff) {
+    helper.setConstraintCoefficient(index, v.getIndex(), coeff);
+  }
+
+  /** Clear all terms. */
+  public void clearTerms() {
+    helper.clearConstraintTerms(index);
+  }
+
   /** Inline setter */
   public LinearConstraint withName(String name) {
     setName(name);

ortools/linear_solver/csharp/ModelBuilder.cs

@@ -187,28 +187,88 @@ public LinearConstraint AddLinearConstraint(LinearExpr expr, double lb, double u
         return lin;
     }
 
+    /// Rebuilds a linear constraint from its index.
+    public LinearConstraint ConstraintFromIndex(int index)
+    {
+        return new LinearConstraint(helper_, index);
+    }
+
     /// <summary>
-    /// Returns the number of variables in the model.
+    /// Adds an enforced Linear constraint to the model.
     /// </summary>
-    public int VariablesCount()
+    /// <param name="lin">A bounded linear expression</param>
+    /// <param name="iVar>The indicator variable of the constraint.</param>
+    /// <param name="iValue>The indicator value of the constraint.</param>
+    /// <returns>A linear expression</returns>
+    /// <exception cref="ArgumentException">Throw when the constraint is not supported by the linear solver</exception>
+    public EnforcedLinearConstraint AddEnforced(BoundedLinearExpression lin, Variable iVar, bool iValue)
     {
-        return helper_.VariablesCount();
+        switch (lin.CtType)
+        {
+        case BoundedLinearExpression.Type.BoundExpression: {
+            return AddEnforcedLinearConstraint(lin.Left, lin.Lb, lin.Ub, iVar, iValue);
+        }
+        case BoundedLinearExpression.Type.VarEqVar: {
+            return AddEnforcedLinearConstraint(lin.Left - lin.Right, 0, 0, iVar, iValue);
+        }
+        case BoundedLinearExpression.Type.VarEqCst: {
+            return AddEnforcedLinearConstraint(lin.Left, lin.Lb, lin.Lb, iVar, iValue);
+        }
+        default: {
+            throw new ArgumentException("Cannot use '" + lin.ToString() + "' as a linear constraint.");
+        }
+        }
     }
 
     /// <summary>
-    /// Returns the number of constraints in the model.
+    /// Adds the constraint iVar == iValue => expr in [lb, ub].
     /// </summary>
-    public int ConstraintsCount()
+    /// <param name="expr">The constrained expression</param>
+    /// <param name="lb">the lower bound of the constraint</param>
+    /// <param name="ub">the upper bound of the constraint</param>
+    /// <param name="iVar">the indicator variable of the constraint</param>
+    /// <param name="iValue">the indicator value of the constraint</param>
+    /// <returns>the enforced linear constraint</returns>
+    public EnforcedLinearConstraint AddEnforcedLinearConstraint(LinearExpr expr, double lb, double ub, Variable iVar,
+                                                                bool iValue)
     {
-        return helper_.ConstraintsCount();
+        var dict = tmp_var_value_map_;
+        dict.Clear();
+        double offset = LinearExpr.GetVarValueMap(expr, dict, tmp_terms_);
+        EnforcedLinearConstraint lin = new EnforcedLinearConstraint(helper_);
+        lin.IndicatorVariable = iVar;
+        lin.IndicatorValue = iValue;
+        foreach (KeyValuePair<int, double> term in dict)
+        {
+            helper_.AddEnforcedConstraintTerm(lin.Index, term.Key, term.Value);
+        }
+        if (lb == Double.NegativeInfinity || lb == Double.PositiveInfinity)
+        {
+            lin.LowerBound = lb;
+        }
+        else
+        {
+            lin.LowerBound = lb - offset;
+        }
+        if (ub == Double.NegativeInfinity || ub == Double.PositiveInfinity)
+        {
+            lin.UpperBound = ub;
+        }
+        else
+        {
+            lin.UpperBound = ub - offset;
+        }
+        return lin;
     }
 
     /// Rebuilds a linear constraint from its index.
-    public LinearConstraint ConstraintFromIndex(int index)
+    public EnforcedLinearConstraint EnforcedConstraintFromIndex(int index)
     {
-        return new LinearConstraint(helper_, index);
+        return new EnforcedLinearConstraint(helper_, index);
     }
 
+    // Objective.
+
     /// <summary>
     /// Minimize expression.
     /// </summary>
@@ -265,18 +325,36 @@ public double ObjectiveOffset
     /// <summary>
     /// Remove all hints from the model.
     /// </summary>
-    public void ClearHints() {
+    public void ClearHints()
+    {
         helper_.ClearHints();
     }
 
     /// <summary>
-    /// Adds var == value as a hint to the model.  Note that variables must not appear more than once in the list of hints.
+    /// Adds var == value as a hint to the model.  Note that variables must not appear more than once in the list of
+    /// hints.
     /// </summary>
     public void AddHint(Variable var, double value)
     {
         helper_.AddHint(var.Index, value);
     }
 
+    /// <summary>
+    /// Returns the number of variables in the model.
+    /// </summary>
+    public int VariablesCount()
+    {
+        return helper_.VariablesCount();
+    }
+
+    /// <summary>
+    /// Returns the number of constraints in the model.
+    /// </summary>
+    public int ConstraintsCount()
+    {
+        return helper_.ConstraintsCount();
+    }
+
     /// <summary>
     /// The name of the model.
     /// </summary>