switch to returning an array of actions instead of a linked list

- attempts to keep the same move ordering as the list method
- saves ~170msec on a depth 7 search for a given board configuration
- there is room to improve the pre-allocation size estimates, these
  bounds are not obviously tight and it may or may not be faster to
  have tighter bounds or even some form of estimation

1 files changed, 7 insertions, 13 deletions

diff --git a/include/actions.h b/include/actions.h
index 1550cce..0127119 100644
--- a/include/actions.h
+++ b/include/actions.h
@@ -43,15 +43,6 @@ typedef uint32_t action_t;
   ((type) | (loc) << A_LOC_SHIFT | (data0) << A_DATA0_SHIFT |                  \
    (data1) << A_DATA1_SHIFT)
 
-typedef struct action_node_s {
-  struct action_node_s *next;
-  action_t action;
-} action_node_t;
-
-typedef struct action_list_s {
-  struct action_node_s *head, *tail;
-  uint32_t length;
-} action_list_t;
 
 // ===================================================================
 // Variables
@@ -63,11 +54,14 @@ extern int8_t move_deltas[4];
 // Methods
 // ===================================================================
 
-void action_list_init(const uint8_t board_size);
-void action_list_free(action_list_t *list);
-action_list_t *action_list_generate(tak_state_p state);
+void actions_init(const uint8_t board_size);
+void actions_free(action_t *actions);
 
-int action_move_to_front(const action_t action, action_list_t *list);
+action_t *actions_generate(tak_state_p state, uint32_t *num_actions);
+char action_in_list(action_t action, action_t *actions,
+                    const uint32_t num_actions);
+void action_move_to_front(action_t action, action_t *actions,
+                          const uint32_t num_actions);
 
 void action_take(tak_state_p state, const action_t action);
 void action_undo(tak_state_p state, const action_t action);