1 files changed, 13 insertions, 2 deletions

diff --git a/native/include/lp_common.h b/native/include/lp_common.h
index 06519d1..d5a8a60 100644
--- a/native/include/lp_common.h
+++ b/native/include/lp_common.h
@@ -22,10 +22,13 @@ enum blocking_type
 class VarMapper {
 private:
         hashmap<uint64_t, unsigned int> map;
+        unsigned int next_var;
 
         void insert(uint64_t key)
         {
-                unsigned int idx = map.size();
+                assert(next_var < UINT_MAX);
+
+                unsigned int idx = next_var++;
                 map[key] = idx;
         }
 
@@ -41,6 +44,9 @@ private:
         }
 
 public:
+        VarMapper(unsigned int start_var = 0)
+                : next_var(start_var)
+        {}
 
         unsigned int lookup(unsigned int task_id, unsigned int res_id, unsigned int req_id,
                             blocking_type type)
@@ -56,10 +62,15 @@ public:
                 map.clear();
         }
 
-        unsigned int get_num_vars()
+        unsigned int get_num_vars() const
         {
                 return map.size();
         }
+
+        unsigned int get_next_var() const
+        {
+                return next_var;
+        }
 };
 
 void set_blocking_objective(