Update movepick.cpp

Author: winapiadmin

movepick.cpp

@@ -3,8 +3,39 @@
 #include <position.h>
 using namespace chess;
 namespace engine {
+    Value historyHeuristic[SQUARE_NB][SQUARE_NB]{};
+    Move killerMoves[MAX_PLY][2];
     void movepick::orderMoves(chess::Board & board, chess::Movelist & moves, chess::Move ttMove, int ply)
     {
-        std::vector<std::pair<chess::Move,Value>> moves_;
+        std::vector<std::pair<chess::Move, Value>> scoredMoves;
+        scoredMoves.reserve(moves.size());
+    
+        for (const auto& move : moves)
+        {
+            Value score = 0;
+    
+            if (move == ttMove)
+                score = 10000;
+            else if (board.isCapture(move))
+                score = 
+                    ((move.type() & EN_PASSANT)==0?piece_value(board.at<PieceType>(move.to())):piece_value(PAWN))*10 - piece_value(board.at<PieceType>(move.from()));
+            else if (move == killerMoves[ply][0])
+                score = 8500;
+            else if (move == killerMoves[ply][1])
+                score = 8000;
+            else
+                score = historyHeuristic[move.from().index()][move.to().index()];
+    
+            scoredMoves.emplace_back(move, score);
+        }
+    
+        std::stable_sort(scoredMoves.begin(), scoredMoves.end(),
+            [](const auto& a, const auto& b)
+            {
+                return a.second > b.second;
+            });
+    
+        for (size_t i = 0; i < scoredMoves.size(); ++i)
+            moves[i] = scoredMoves[i].first;
     }
 }