From be70ffcf01f103235f1cdb06352a48f004603b43 Mon Sep 17 00:00:00 2001
From: Varun Agrawal <varagrawal@gmail.com>
Date: Thu, 8 Jun 2023 10:36:21 -0400
Subject: [PATCH] remove excessive Unique call to improve efficiency

---
 gtsam/discrete/DecisionTree-inl.h | 6 +++---
 gtsam/discrete/DecisionTree.h     | 6 ++++--
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/gtsam/discrete/DecisionTree-inl.h b/gtsam/discrete/DecisionTree-inl.h
index 58de338a8..16a926271 100644
--- a/gtsam/discrete/DecisionTree-inl.h
+++ b/gtsam/discrete/DecisionTree-inl.h
@@ -627,7 +627,7 @@ namespace gtsam {
         NodePtr fi = compose(functions.begin(), functions.end(), label);
         choiceOnHighestLabel->push_back(fi);
       }
-      return Choice::Unique(choiceOnHighestLabel);
+      return choiceOnHighestLabel;
     }
   }
 
@@ -691,8 +691,8 @@ namespace gtsam {
   }
 
   /****************************************************************************/
-  // Take a range of labels and a corresponding range of values,
-  // and creates a decision tree.
+  // Top-level factory method, which takes a range of labels and a corresponding
+  // range of values, and creates a decision tree.
   template<typename L, typename Y>
   template<typename It, typename ValueIt>
   typename DecisionTree<L, Y>::NodePtr DecisionTree<L, Y>::create(
diff --git a/gtsam/discrete/DecisionTree.h b/gtsam/discrete/DecisionTree.h
index a2b05070b..a5d890ab5 100644
--- a/gtsam/discrete/DecisionTree.h
+++ b/gtsam/discrete/DecisionTree.h
@@ -142,8 +142,10 @@ namespace gtsam {
     template <typename It, typename ValueIt>
     NodePtr build(It begin, It end, ValueIt beginY, ValueIt endY) const;
 
-    /** Internal helper function to create from keys, cardinalities,
-     * and Y values
+    /** Internal helper function to create from
+     * keys, cardinalities, and Y values.
+     * Calls `build` which builds thetree bottom-up,
+     * before we prune in a top-down fashion.
      */
     template <typename It, typename ValueIt>
     NodePtr create(It begin, It end, ValueIt beginY, ValueIt endY) const;