summaryrefslogtreecommitdiff
path: root/include
diff options
context:
space:
mode:
Diffstat (limited to 'include')
-rw-r--r--include/ct1986.c23
-rw-r--r--include/ct1986.h6
2 files changed, 23 insertions, 6 deletions
diff --git a/include/ct1986.c b/include/ct1986.c
index bc48110..706640e 100644
--- a/include/ct1986.c
+++ b/include/ct1986.c
@@ -121,12 +121,12 @@ previous_ply(void) {
if ((min == 0) && (w == WIN_ROAD_BLACK \
|| w == WIN_FLAT_BLACK \
|| w == WIN_DRAGON)) { \
- this = +2; \
+ this = +3; \
} else if ((min > 0) \
&& (w == WIN_ROAD_WHITE \
|| w == WIN_FLAT_WHITE \
|| w == WIN_DRAGON)) { \
- this = -2; \
+ this = -3; \
} /* Otherwise decide what to do based on our depth */ \
} else if (cur_depth == max_depth) { \
/* We're at the bottom, evaluate */ \
@@ -134,20 +134,24 @@ previous_ply(void) {
} else { \
/* We're not at the bottom, recurse first */ \
next_ply(); \
- this = ct1986_minimax(cur_depth + 1, max_depth, 1-min); \
+ this = ct1986_minimax(cur_depth + 1, max_depth, 1-min, alpha, beta); \
previous_ply(); \
} \
if ( (min && (this < optimal)) \
|| ((min==0) && (this > optimal))) { \
optimal = this; \
+ if (min) { \
+ if (this < beta) beta = this; \
+ } else { \
+ if (this > alpha) alpha = this; \
+ } \
if (cur_depth == 0) { store; }; \
} \
}
-
float
ct1986_minimax(const uint8_t cur_depth, const uint8_t max_depth,
- const uint8_t min) {
+ const uint8_t min, float alpha, float beta) {
enum E_RESULT r;
enum WIN_TYPE w;
uint16_t colours_backup[board_size];
@@ -227,6 +231,8 @@ ct1986_minimax(const uint8_t cur_depth, const uint8_t max_depth,
}
}
}
+ // Prune
+ if (alpha >= beta) return optimal;
}
}
}
@@ -250,6 +256,8 @@ ct1986_minimax(const uint8_t cur_depth, const uint8_t max_depth,
celldat[loc] = 0;
white_count = white_count_backup;
black_count = black_count_backup;
+ // Prune
+ if (alpha >= beta) return optimal;
}
}
}
@@ -258,3 +266,8 @@ ct1986_minimax(const uint8_t cur_depth, const uint8_t max_depth,
}
return optimal;
}
+
+inline float
+ct1986_generate(const uint8_t max_depth) {
+ return ct1986_minimax(0, max_depth, 0, -10, 10);
+}
diff --git a/include/ct1986.h b/include/ct1986.h
index 877c301..ef56c1f 100644
--- a/include/ct1986.h
+++ b/include/ct1986.h
@@ -11,9 +11,13 @@ ct1986_evaluate_black_win(void);
// Generate PTN of the ````best'''' action and store it in ct1986_ptn,
// along with its value as the return. The ct1986_display_progress
// function pointer is called on every new square.
+
+float ct1986_generate(const uint8_t max_depth);
+
+// Access to the internal method
float
ct1986_minimax(const uint8_t cur_depth, const uint8_t max_depth,
- const uint8_t min);
+ const uint8_t min, float alpha, float beta);
extern char ct1986_ptn[9];
extern float ct1986_optimal;