position: 解决特定条件下每3次go出现1个 draw 的问题

nRepetition 由静态变量改为全局变量

用例:
position fen O@@OOOO@/OOO**@O@/@O@@O@@O b m p 10 0 12 0 0 2 14 moves (3,4)->(2,4) (3,5)->(3,4) (2,4)->(2,5)

src/position.cpp

@@ -744,8 +744,16 @@ int Position::set_position(const struct Rule *newRule)
     return -1;
 }
 
+#ifdef THREEFOLD_REPETITION
+extern int nRepetition;
+#endif // THREEFOLD_REPETITION
+
 bool Position::reset()
 {
+#ifdef THREEFOLD_REPETITION
+    nRepetition = 0;
+#endif // THREEFOLD_REPETITION
+
     gamePly = 0;
     st.rule50 = 0;
 

src/search.cpp

@@ -78,6 +78,9 @@ void Search::clear()
     Threads.clear();
 }
 
+#ifdef THREEFOLD_REPETITION
+int nRepetition;
+#endif // THREEFOLD_REPETITION
 
 /// Thread::search() is the main iterative deepening loop. It calls search()
 /// repeatedly with increasing depth until the allocated thinking time has been
@@ -105,8 +108,6 @@ int Thread::search()
 #endif
 
 #ifdef THREEFOLD_REPETITION
-    static int nRepetition = 0;
-
     if (rootPos->get_phase() == PHASE_MOVING) {
         Key key = rootPos->key();
 

src/uci.cpp

@@ -41,6 +41,11 @@ using namespace std;
 
 extern vector<string> setup_bench(Position *, istream &);
 
+#ifdef THREEFOLD_REPETITION
+extern int nRepetition;
+extern vector<Key> moveHistory;
+#endif // THREEFOLD_REPETITION
+
 namespace
 {
 
@@ -69,11 +74,19 @@ void position(Position *pos, istringstream &is)
     else
         return;
 
+#ifdef THREEFOLD_REPETITION
+    nRepetition = 0;
+    moveHistory.clear();
+#endif // THREEFOLD_REPETITION
+    
     pos->set(fen, Threads.main());
 
     // Parse move list (if any)
     while (is >> token && (m = UCI::to_move(pos, token)) != MOVE_NONE) {
         pos->do_move(m);
+#ifdef THREEFOLD_REPETITION
+        moveHistory.push_back(pos->key());
+#endif // THREEFOLD_REPETITION
     }
 
     Threads.main()->us = pos->sideToMove;
@@ -113,6 +126,11 @@ void go(Position *pos)
 #ifdef UCI_AUTO_RE_GO
     begin:
 #endif
+
+#ifdef THREEFOLD_REPETITION
+    nRepetition = 0;
+#endif // THREEFOLD_REPETITION
+
     Threads.start_thinking(pos);
 
     if (pos->get_phase() == PHASE_GAMEOVER)