From d9346acb976da635065d6245754e6b4594c9eb28 Mon Sep 17 00:00:00 2001
From: Ted Turocy <ted.turocy@gmail.com>
Date: Wed, 18 Sep 2024 16:36:32 +0100
Subject: [PATCH] Simplify tracking of information sets to minimum needed, as
 rows are no longer a concept.

---
 src/solvers/enumpoly/efgpoly.cc |  2 +-
 src/solvers/enumpoly/sfg.cc     |  6 +-----
 src/solvers/enumpoly/sfg.h      | 14 +++-----------
 3 files changed, 5 insertions(+), 17 deletions(-)

diff --git a/src/solvers/enumpoly/efgpoly.cc b/src/solvers/enumpoly/efgpoly.cc
index ba4714d3f..875a0a5d1 100644
--- a/src/solvers/enumpoly/efgpoly.cc
+++ b/src/solvers/enumpoly/efgpoly.cc
@@ -75,7 +75,7 @@ gPoly<double> BuildSequenceVariable(ProblemData &p_data, const GameSequence &p_s
 
 ProblemData::ProblemData(const BehaviorSupportProfile &p_support)
   : support(p_support), SF(p_support),
-    Space(new gSpace(SF.TotalNumSequences() - SF.NumPlayerInfosets() - SF.NumPlayers())),
+    Space(new gSpace(SF.TotalNumSequences() - SF.NumInfosets() - SF.NumPlayers())),
     Lex(new term_order(Space, lex))
 {
   for (auto player : p_support.GetGame()->GetPlayers()) {
diff --git a/src/solvers/enumpoly/sfg.cc b/src/solvers/enumpoly/sfg.cc
index d7f18dba7..4c9caab1f 100644
--- a/src/solvers/enumpoly/sfg.cc
+++ b/src/solvers/enumpoly/sfg.cc
@@ -33,7 +33,6 @@ Sfg::Sfg(const BehaviorSupportProfile &S) : support(S)
     m_sequences[player] = {{player, nullptr}};
     m_sequenceColumns[player] = {{nullptr, 1}};
     m_actionParents[player] = {};
-    infoset_row[player] = {};
   }
 
   PureSequenceProfile parent;
@@ -76,10 +75,7 @@ void Sfg::BuildSequences(const GameNode &n, PureSequenceProfile &p_previousActio
     }
   }
   else {
-    auto &player_infoset_row = infoset_row[n->GetPlayer()];
-    if (player_infoset_row.find(n->GetInfoset()) == player_infoset_row.end()) {
-      player_infoset_row[n->GetInfoset()] = player_infoset_row.size() + 1;
-    }
+    m_infosets.insert(n->GetInfoset());
     for (auto action : support.GetActions(n->GetInfoset())) {
       m_actionParents[n->GetPlayer()][action] = p_previousActions[n->GetPlayer()];
       p_previousActions[n->GetPlayer()] = action;
diff --git a/src/solvers/enumpoly/sfg.h b/src/solvers/enumpoly/sfg.h
index 02b864592..dcfe08a20 100644
--- a/src/solvers/enumpoly/sfg.h
+++ b/src/solvers/enumpoly/sfg.h
@@ -55,7 +55,7 @@ class Sfg {
   std::map<GamePlayer, std::map<GameAction, int>> m_sequenceColumns;
   NDArray<Rational> SF;                                            // sequence form
   std::map<std::pair<GameInfoset, GameAction>, int> m_constraints; // (sparse) constraint matrices
-  std::map<GamePlayer, std::map<GameInfoset, int>> infoset_row;
+  std::set<GameInfoset> m_infosets; // infosets actually reachable given support
   std::map<GamePlayer, std::map<GameAction, GameAction>> m_actionParents;
 
   void BuildSequences(const GameNode &, PureSequenceProfile &);
@@ -88,8 +88,6 @@ class Sfg {
     return m_sequences.at(p_player).cend();
   }
 
-  int NumInfosets(const GamePlayer &p_player) const { return infoset_row.at(p_player).size(); }
-
   const Array<int> &NumSequences() const { return SF.GetIndexDimension(); }
 
   int TotalNumSequences() const
@@ -98,16 +96,10 @@ class Sfg {
     return std::accumulate(dim.cbegin(), dim.cend(), 0);
   }
 
-  int NumPlayerInfosets() const
-  {
-    auto players = support.GetGame()->GetPlayers();
-    return std::accumulate(
-        players.cbegin(), players.cend(), 0,
-        [this](int accum, const GamePlayer &player) { return accum + NumInfosets(player); });
-  }
-
   int NumPlayers() const { return support.GetGame()->NumPlayers(); }
 
+  size_t NumInfosets() const { return m_infosets.size(); }
+
   const Rational &GetPayoff(const Array<int> &index, int pl) const { return SF.at(index, pl); }
 
   int GetConstraintEntry(const GameInfoset &p_infoset, const GameAction &p_action) const