From 325bd45dbc9c44d346d81ceed5625294681e7a9d Mon Sep 17 00:00:00 2001
From: Ted Turocy <ted.turocy@gmail.com>
Date: Fri, 13 Sep 2024 11:49:11 +0100
Subject: [PATCH] Remove unneeded tracking of previous information set.

---
 src/solvers/enumpoly/sfg.cc | 11 ++++-------
 src/solvers/enumpoly/sfg.h  |  2 +-
 2 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/src/solvers/enumpoly/sfg.cc b/src/solvers/enumpoly/sfg.cc
index 56ff16e3b..bacfbf039 100644
--- a/src/solvers/enumpoly/sfg.cc
+++ b/src/solvers/enumpoly/sfg.cc
@@ -57,7 +57,6 @@ Sfg::Sfg(const BehaviorSupportProfile &S) : support(S), m_dim(support.GetGame()-
   SF = NDArray<Rational>(m_dim, support.GetGame()->NumPlayers());
 
   PureSequenceProfile parent;
-  std::map<GamePlayer, GameInfoset> last_infoset;
   for (auto player : support.GetGame()->GetPlayers()) {
     m_sequenceColumns[player] = {{nullptr, 1}};
 
@@ -68,14 +67,13 @@ Sfg::Sfg(const BehaviorSupportProfile &S) : support(S), m_dim(support.GetGame()-
     E.at(player)(1, 1) = Rational(1);
 
     parent[player] = sequences.at(player).front();
-    last_infoset[player] = nullptr;
   }
 
-  MakeSequenceForm(support.GetGame()->GetRoot(), Rational(1), one, last_infoset, parent);
+  MakeSequenceForm(support.GetGame()->GetRoot(), Rational(1), one, parent);
 }
 
 void Sfg::MakeSequenceForm(const GameNode &n, const Rational &prob, const Array<int> &seq,
-                           std::map<GamePlayer, GameInfoset> iset, PureSequenceProfile parent)
+                           PureSequenceProfile parent)
 {
   if (n->GetOutcome()) {
     for (int pl = 1; pl <= seq.Length(); pl++) {
@@ -89,12 +87,11 @@ void Sfg::MakeSequenceForm(const GameNode &n, const Rational &prob, const Array<
     for (auto action : n->GetInfoset()->GetActions()) {
       MakeSequenceForm(n->GetChild(action),
                        prob * static_cast<Rational>(n->GetInfoset()->GetActionProb(action)), seq,
-                       iset, parent);
+                       parent);
     }
   }
   else {
     int pl = n->GetPlayer()->GetNumber();
-    iset[n->GetPlayer()] = n->GetInfoset();
 
     E.at(n->GetPlayer())(infoset_row[n->GetPlayer()][n->GetInfoset()], seq[pl]) = Rational(1);
     std::shared_ptr<SequenceRep> myparent(parent[n->GetPlayer()]);
@@ -111,7 +108,7 @@ void Sfg::MakeSequenceForm(const GameNode &n, const Rational &prob, const Array<
       }
       snew[pl] = m_sequenceColumns[n->GetPlayer()][action];
       E.at(n->GetPlayer())(infoset_row[n->GetPlayer()][n->GetInfoset()], snew[pl]) = Rational(-1);
-      MakeSequenceForm(n->GetChild(action), prob, snew, iset, parent);
+      MakeSequenceForm(n->GetChild(action), prob, snew, parent);
     }
   }
 }
diff --git a/src/solvers/enumpoly/sfg.h b/src/solvers/enumpoly/sfg.h
index ccff90b79..764e0ba1e 100644
--- a/src/solvers/enumpoly/sfg.h
+++ b/src/solvers/enumpoly/sfg.h
@@ -65,7 +65,7 @@ class Sfg {
   std::map<GamePlayer, std::map<GameAction, GameAction>> m_actionParents;
 
   void MakeSequenceForm(const GameNode &, const Rational &, const Array<int> &,
-                        std::map<GamePlayer, GameInfoset>, PureSequenceProfile);
+                        PureSequenceProfile);
 
   void ComputeNumSequences(const GameNode &, std::map<GamePlayer, GameAction> &);