From e7d71ffcd3927b1fd00b38599e94a796e09ea0fb Mon Sep 17 00:00:00 2001
From: "lperron@google.com"
 <lperron@google.com@59fed7e4-672f-1a80-1451-5ac2ff6d83f1>
Date: Tue, 23 Jul 2013 16:09:40 +0000
Subject: [PATCH] correct ismember code

---
 src/constraint_solver/expr_cst.cc | 71 ++++++++++++++++++++-----------
 1 file changed, 45 insertions(+), 26 deletions(-)

diff --git a/src/constraint_solver/expr_cst.cc b/src/constraint_solver/expr_cst.cc
index d7a04ce700..8b360eff9b 100644
--- a/src/constraint_solver/expr_cst.cc
+++ b/src/constraint_solver/expr_cst.cc
@@ -976,20 +976,50 @@ class IsMemberCt : public Constraint {
   }
 
   virtual void Post() {
-    demon_ = solver()->MakeConstraintInitialPropagateCallback(this);
+    demon_ = MakeConstraintDemon0(
+        solver(), this, &IsMemberCt::VarDomain, "VarDomain");
     if (!var_->Bound()) {
       var_->WhenDomain(demon_);
     }
     if (!boolvar_->Bound()) {
-      boolvar_->WhenBound(demon_);
+      Demon* const bdemon = MakeConstraintDemon0(
+          solver(), this, &IsMemberCt::TargetBound, "TargetBound");
+      boolvar_->WhenBound(bdemon);
     }
   }
 
   virtual void InitialPropagate() {
-    if (boolvar_->Min() == 1LL) {
-      demon_->inhibit(solver());
-      var_->SetValues(values_.RawData(), values_.size());
-    } else if (boolvar_->Max() == 1LL) {
+    boolvar_->SetRange(0, 1);
+    if (boolvar_->Bound()) {
+      TargetBound();
+    } else {
+      VarDomain();
+    }
+  }
+
+  virtual string DebugString() const {
+    return StringPrintf("IsMemberCt(%s, %s, %s)",
+                        var_->DebugString().c_str(),
+                        values_.DebugString().c_str(),
+                        boolvar_->DebugString().c_str());
+  }
+
+  virtual void Accept(ModelVisitor* const visitor) const {
+    visitor->BeginVisitConstraint(ModelVisitor::kIsMember, this);
+    visitor->VisitIntegerExpressionArgument(ModelVisitor::kExpressionArgument,
+                                            var_);
+    visitor->VisitConstIntArrayArgument(ModelVisitor::kValuesArgument,
+                                        values_);
+    visitor->VisitIntegerExpressionArgument(ModelVisitor::kTargetArgument,
+                                            boolvar_);
+    visitor->EndVisitConstraint(ModelVisitor::kIsMember, this);
+  }
+
+ private:
+  void VarDomain() {
+    if (boolvar_->Bound()) {
+      TargetBound();
+    } else {
       for (int offset = 0; offset < values_.size(); ++offset) {
         const int candidate = (support_ + offset) % values_.size();
         if (var_->Contains(values_[candidate])) {
@@ -1020,31 +1050,20 @@ class IsMemberCt : public Constraint {
       // No positive support, setting boolvar to false.
       demon_->inhibit(solver());
       boolvar_->SetValue(0);
-    } else {  // boolvar_ set to 0.
+    }
+  }
+
+  void TargetBound() {
+    DCHECK(boolvar_->Bound());
+    if (boolvar_->Min() == 1LL) {
+      demon_->inhibit(solver());
+      var_->SetValues(values_.RawData(), values_.size());
+    } else {
       demon_->inhibit(solver());
       var_->RemoveValues(values_.RawData(), values_.size());
     }
   }
 
-  virtual string DebugString() const {
-    return StringPrintf("IsMemberCt(%s, %s, %s)",
-                        var_->DebugString().c_str(),
-                        values_.DebugString().c_str(),
-                        boolvar_->DebugString().c_str());
-  }
-
-  virtual void Accept(ModelVisitor* const visitor) const {
-    visitor->BeginVisitConstraint(ModelVisitor::kIsMember, this);
-    visitor->VisitIntegerExpressionArgument(ModelVisitor::kExpressionArgument,
-                                            var_);
-    visitor->VisitConstIntArrayArgument(ModelVisitor::kValuesArgument,
-                                        values_);
-    visitor->VisitIntegerExpressionArgument(ModelVisitor::kTargetArgument,
-                                            boolvar_);
-    visitor->EndVisitConstraint(ModelVisitor::kIsMember, this);
-  }
-
- private:
   IntVar* const var_;
   hash_set<int64> values_as_set_;
   ConstIntArray values_;