Keep a count of live Steps

[slidingtile] / sliding_tile_lib.h

diff --git a/sliding_tile_lib.h b/sliding_tile_lib.h
index c5d0a8bc66c99b7480d06a1c2b96811de9bbe6b6..11d9de33b810b8410a06e37fc240b69a8270bc7f 100644 (file)
--- a/sliding_tile_lib.h
+++ b/sliding_tile_lib.h
@@ -2,7 +2,10 @@
 #define _SLIDING_TILE_LIB_H
 
 #include <istream>
+#include <memory>
 #include <ostream>
+#include <string>
+#include <vector>
 
 const int BOARD_DIM = 4;
 const int BOARD_SIZE = BOARD_DIM * BOARD_DIM;
@@ -18,10 +21,30 @@ struct Board {
   InvertedBoard invert() const;
   int distance(const Board& o) const;
   int distance(const InvertedBoard& invo) const;
+  bool operator==(const Board& o) const;
+  bool operator!=(const Board& o) const;
+  bool operator<(const Board& o) const;
 };
 std::istream& operator>>(std::istream& is, Board& board);
 std::ostream& operator<<(std::ostream& os, const Board& board);
 
-extern signed char adjacent[BOARD_SIZE][5];
+struct Step {
+  Step(Board board, std::shared_ptr<Step> prev);
+  ~Step();
+
+  Board board;
+  std::shared_ptr<Step> prev;
+
+  std::vector<std::shared_ptr<Step>> successors(std::shared_ptr<Step> shared_this) const;
+  int length() const;
+  int cost(const InvertedBoard& invgoal) const;
+
+  static signed char adjacent[BOARD_SIZE][5];
+  static int count;
+};
+std::ostream& operator<<(std::ostream& os, const Step& step);
+
+std::shared_ptr<Step> find_path(const std::string& start, const std::string& goal);
+std::shared_ptr<Step> find_path(const Board& start, const Board& goal);
 
 #endif /* _SLIDING_TILE_LIB_H */