diff --git a/shenzhen_solitaire/c++/CMakeLists.txt b/shenzhen_solitaire/c++/CMakeLists.txt
index de200d7..89b9c8c 100644
--- a/shenzhen_solitaire/c++/CMakeLists.txt
+++ b/shenzhen_solitaire/c++/CMakeLists.txt
@@ -5,6 +5,7 @@ cmake_minimum_required(VERSION 3.16)
 set(CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake")
 include( "common" )
 
-add_library(board STATIC lib/board.cpp)
+add_library(board STATIC lib/board.cpp lib/card.cpp lib/goal.cpp)
 set_property(TARGET board PROPERTY CXX_STANDARD 17)
-target_include_directories(board PUBLIC include)
\ No newline at end of file
+target_include_directories(board PUBLIC include)
+add_subdirectory(auxiliary)
\ No newline at end of file
diff --git a/shenzhen_solitaire/c++/auxiliary/CMakeLists.txt b/shenzhen_solitaire/c++/auxiliary/CMakeLists.txt
new file mode 100644
index 0000000..88a686c
--- /dev/null
+++ b/shenzhen_solitaire/c++/auxiliary/CMakeLists.txt
@@ -0,0 +1,12 @@
+find_package(SWIG REQUIRED)
+include(${SWIG_USE_FILE})
+
+find_package(PythonLibs REQUIRED)
+
+set_property(SOURCE swig.i PROPERTY CPLUSPLUS ON)
+swig_add_library(shenzhen_python TYPE SHARED LANGUAGE PYTHON SOURCES swig.i)
+
+target_include_directories(shenzhen_python PUBLIC ${PYTHON_INCLUDE_PATH})
+target_link_libraries(shenzhen_python PUBLIC board)
+
+set_property(TARGET shenzhen_python PROPERTY CXX_STANDARD 17)
diff --git a/shenzhen_solitaire/c++/auxiliary/swig.i b/shenzhen_solitaire/c++/auxiliary/swig.i
new file mode 100644
index 0000000..0d36755
--- /dev/null
+++ b/shenzhen_solitaire/c++/auxiliary/swig.i
@@ -0,0 +1,54 @@
+%module shenzhen
+%{
+    #include "board.hpp"
+    #include "card.hpp"
+    #include "goal.hpp"
+%}
+
+namespace solitaire {
+enum class CardType : int { Zhong, Bai, Fa, Hua, Red, Green, Black };
+
+auto isNormalCardType(CardType type) -> bool;
+
+struct Card {
+  CardType type;
+  int value;
+  auto toString() const noexcept -> std::string;
+};
+
+class Goal {
+  std::array<std::optional<Card>, 3> goal{};
+  auto getEmptyId() -> std::optional<int>;
+
+public:
+  auto getId(CardType suit) const noexcept -> std::optional<int>;
+  auto get(CardType suit) const noexcept -> std::optional<int>;
+
+  void set(CardType suit, int value) noexcept;
+  void inc(CardType suit) noexcept;
+};
+
+struct BunkerField {
+  std::optional<Card> card;
+  bool empty{};
+  bool closed{};
+};
+
+inline constexpr int MAX_ROW_SIZE = 13;
+inline constexpr int MAX_COLUMN_SIZE = 8;
+
+class Stack {
+  std::array<std::optional<Card>, MAX_COLUMN_SIZE> values{};
+};
+
+struct Board {
+  std::array<Stack, MAX_ROW_SIZE> field{};
+  std::array<BunkerField, 3> bunker{};
+  Goal goal{};
+  bool flower_gone{};
+
+   auto solved() const noexcept -> bool;
+   auto hash() const noexcept -> std::size_t;
+   auto correct() const noexcept -> bool;
+};
+}
\ No newline at end of file
diff --git a/shenzhen_solitaire/c++/include/board.hpp b/shenzhen_solitaire/c++/include/board.hpp
index 9cd1589..2a7c05b 100644
--- a/shenzhen_solitaire/c++/include/board.hpp
+++ b/shenzhen_solitaire/c++/include/board.hpp
@@ -1,27 +1,35 @@
+#pragma once
+#include "card.hpp"
+#include "goal.hpp"
+
 #include <array>
+#include <cassert>
 #include <optional>
 
 namespace solitaire {
-class Card {
-    bool isNormalCard();
-    bool isSpecialCard();
+
+struct BunkerField {
+  std::optional<Card> card;
+  bool empty{};
+  bool closed{};
 };
 
-struct BunkerField{
-    Card card;
-    bool empty;
-    bool closed;
+inline constexpr int MAX_ROW_SIZE = 13;
+inline constexpr int MAX_COLUMN_SIZE = 8;
+
+class Stack {
+  std::array<std::optional<Card>, MAX_COLUMN_SIZE> values{};
 };
 
-class Board {
-public:
-  static constexpr int MAX_ROW_SIZE = 13;
-  static constexpr int MAX_COLUMN_SIZE = 8;
+struct Board {
+  std::array<Stack, MAX_ROW_SIZE> field{};
+  std::array<BunkerField, 3> bunker{};
+  Goal goal{};
+  bool flower_gone{};
 
-private:
-  std::array<std::array<Card, MAX_COLUMN_SIZE>, MAX_ROW_SIZE> field;
-  std::array<BunkerField, 3> bunker;
-  std::array<std::optional<Card>, 3> goal; 
-  bool flower_gone;
+  [[nodiscard]] auto solved() const noexcept -> bool;
+  [[nodiscard]] auto hash() const noexcept -> std::size_t;
+  [[nodiscard]] auto correct() const noexcept -> bool;
 };
+
 } // namespace solitaire
\ No newline at end of file
diff --git a/shenzhen_solitaire/c++/include/card.hpp b/shenzhen_solitaire/c++/include/card.hpp
new file mode 100644
index 0000000..51e1aba
--- /dev/null
+++ b/shenzhen_solitaire/c++/include/card.hpp
@@ -0,0 +1,15 @@
+#pragma once
+#include <cassert>
+#include <string>
+
+namespace solitaire {
+enum class CardType : int { Zhong, Bai, Fa, Hua, Red, Green, Black };
+
+auto isNormalCardType(CardType type) -> bool;
+
+struct Card {
+  CardType type;
+  int value;
+  [[nodiscard]] auto toString() const noexcept -> std::string;
+};
+} // namespace solitaire
\ No newline at end of file
diff --git a/shenzhen_solitaire/c++/include/goal.hpp b/shenzhen_solitaire/c++/include/goal.hpp
new file mode 100644
index 0000000..ec37f44
--- /dev/null
+++ b/shenzhen_solitaire/c++/include/goal.hpp
@@ -0,0 +1,20 @@
+
+#pragma once
+#include "card.hpp"
+
+#include <array>
+#include <optional>
+
+namespace solitaire {
+class Goal {
+  std::array<std::optional<Card>, 3> goal{};
+  auto getEmptyId() -> std::optional<int>;
+
+public:
+  [[nodiscard]] auto getId(CardType suit) const noexcept -> std::optional<int>;
+  [[nodiscard]] auto get(CardType suit) const noexcept -> std::optional<int>;
+
+  void set(CardType suit, int value) noexcept;
+  void inc(CardType suit) noexcept;
+};
+} // namespace solitaire
\ No newline at end of file
diff --git a/shenzhen_solitaire/c++/lib/card.cpp b/shenzhen_solitaire/c++/lib/card.cpp
new file mode 100644
index 0000000..e7e00dc
--- /dev/null
+++ b/shenzhen_solitaire/c++/lib/card.cpp
@@ -0,0 +1,15 @@
+#include "card.hpp"
+namespace solitaire {
+auto
+isNormalCardType(CardType type) -> bool {
+  switch (type) {
+  case CardType::Red:
+  case CardType::Green:
+  case CardType::Black:
+    return true;
+    break;
+  default:
+    return false;
+  }
+}
+} // namespace solitaire
diff --git a/shenzhen_solitaire/c++/lib/goal.cpp b/shenzhen_solitaire/c++/lib/goal.cpp
new file mode 100644
index 0000000..dc4895c
--- /dev/null
+++ b/shenzhen_solitaire/c++/lib/goal.cpp
@@ -0,0 +1,66 @@
+
+#include "goal.hpp"
+
+namespace solitaire {
+auto
+Goal::getEmptyId() -> std::optional<int> {
+  int counter = 0;
+  for (const auto& slot : goal) {
+    if (!slot) {
+      return counter;
+    }
+    ++counter;
+  }
+  return std::nullopt;
+}
+
+[[nodiscard]] auto
+Goal::getId(CardType suit) const noexcept -> std::optional<int> {
+  int counter = 0;
+  for (const auto& slot : goal) {
+    if (slot && slot->type == suit) {
+      return counter;
+    }
+    ++counter;
+  }
+  return std::nullopt;
+}
+
+[[nodiscard]] auto
+Goal::get(CardType suit) const noexcept -> std::optional<int> {
+  if (auto index = getId(suit); index) {
+    return goal[*index]->value;
+  }
+  return std::nullopt;
+}
+
+void
+Goal::set(CardType suit, int value) noexcept {
+  assert(value >= 0);
+  assert(value <= 9);
+
+  const auto card = [&]() -> std::optional<Card> {
+    if (value == 0) {
+      return std::nullopt;
+    }
+    return Card{suit, value};
+  }();
+
+  const int goal_index = [&]() -> int {
+    if (auto index = getId(suit); index) {
+      return *index;
+    }
+    return *getEmptyId();
+  }();
+
+  goal[goal_index] = card;
+}
+
+void
+Goal::inc(CardType suit) noexcept {
+  auto get_value = get(suit);
+  int new_value = get_value ? (*get_value) + 1 : 1;
+  set(suit, new_value);
+}
+
+} // namespace solitaire
\ No newline at end of file