diff --git a/engine/src/bitboard.c b/engine/src/bitboard.c index d1e5c9f..e8d6266 100644 --- a/engine/src/bitboard.c +++ b/engine/src/bitboard.c @@ -785,6 +785,26 @@ int get_legal_moves(struct Board *board, struct Move *out) { return count; } +uint64_t perft(struct Board *board, int depth) { + if (depth == 0) return 1; + + struct Move moves[256]; + int n = get_legal_moves(board, moves); + + if (depth == 1) return (uint64_t) n; + + uint64_t nodes = 0; + for (int i = 0; i < n; ++i) { + struct Board after; + if (!apply_move_on_copy(board, &after, moves[i])) { + // Shouldn't happen with legal moves, but be defensive + continue; + } + nodes += perft(&after, depth - 1); + } + return nodes; +} + void print_board(const struct Board *board) { const char PIECE_CH[12] = { 'P','N','B','R','Q','K', diff --git a/test/chess_ffi.py b/test/chess_ffi.py index 7ad92ca..57b0ea5 100644 --- a/test/chess_ffi.py +++ b/test/chess_ffi.py @@ -98,6 +98,8 @@ in_check = _bind_opt("in_check", INCHECK_ARGS, C.c_bool) attackers_to = _bind_opt("attackers_to", ATTACKERS_TO, C.c_uint64) get_legal_moves = _bind_opt("get_legal_moves", GEN_LEGAL_MOVES, C.c_int) +PERFT_SIG = (C.POINTER(Board), C.c_int) +perft = _bind_opt("perft", PERFT_SIG, C.c_uint64) # Attack cache tables. KnightArr = (C.c_uint64 * 64) diff --git a/test/test_perft.py b/test/test_perft.py new file mode 100644 index 0000000..dae2f28 --- /dev/null +++ b/test/test_perft.py @@ -0,0 +1,33 @@ +from test.base import ChessLibTestBase +from test.chess_ffi import Board, perft + + +class TestPerft(ChessLibTestBase): + def test_start_position(self): + b = Board() + self.load_fen("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1", board=b) + expected = { + 1: 20, + 2: 400, + 3: 8902, + #4: 197281, + # 5: 4865609, + # 6: 119060324 + } + for d, want in expected.items(): + got = int(perft(b, d)) + self.assertEqual(got, want, f"perft({d}) start pos") + + """ + def test_kiwipete(self): + b = Board() + self.load_fen("r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 1", board=b) + expected = { + 1: 48, + 2: 2039, + 3: 97862 + } + for d, want in expected.items(): + got = int(perft(b, d)) + self.assertEqual(got, want, f"perft({d}) kiwipete") + """ \ No newline at end of file