From 0e319ad2b2920683153bd26c4738b5550cd58a1d Mon Sep 17 00:00:00 2001
From: Petr Baudis <pasky@ucw.cz>
Date: Fri, 9 Oct 2009 15:48:52 +0200
Subject: [PATCH] UCT Prior: Add ko prior, by default 0

---
 uct/internal.h |  2 +-
 uct/prior.c    | 13 +++++++++++++
 uct/uct.c      |  2 ++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/uct/internal.h b/uct/internal.h
index 88894f1..3e5dbf0 100644
--- a/uct/internal.h
+++ b/uct/internal.h
@@ -31,7 +31,7 @@ struct uct {
 	/* Equivalent experience for prior knowledge. MoGo paper recommends
 	 * 50 playouts per source; in practice, esp. with RAVE, about 6
 	 * playouts per source seems best. */
-	int eqex, even_eqex, gp_eqex, policy_eqex, b19_eqex, cfgd_eqex, eye_eqex;
+	int eqex, even_eqex, gp_eqex, policy_eqex, b19_eqex, cfgd_eqex, eye_eqex, ko_eqex;
 
 	struct uct_policy *policy;
 	struct tree *t;
diff --git a/uct/prior.c b/uct/prior.c
index 624d534..4f76851 100644
--- a/uct/prior.c
+++ b/uct/prior.c
@@ -50,6 +50,17 @@ uct_prior_eye(struct uct *u, struct tree_node *node, struct prior_map *map)
 }
 
 void
+uct_prior_ko(struct uct *u, struct tree_node *node, struct prior_map *map)
+{
+	/* Favor fighting ko, if we took it le 10 moves ago. */
+	coord_t ko = map->b->last_ko.coord;
+	if (is_pass(ko) || map->b->moves - map->b->last_ko_age > 10 || !map->consider[ko])
+		return;
+	// fprintf(stderr, "prior ko-fight @ %s %s\n", stone2str(map->to_play), coord2sstr(ko, map->b));
+	add_prior_value(map, ko, 1, u->eqex);
+}
+
+void
 uct_prior_b19(struct uct *u, struct tree_node *node, struct prior_map *map)
 {
 	/* Q_{b19} */
@@ -129,6 +140,8 @@ uct_prior(struct uct *u, struct tree_node *node, struct prior_map *map)
 		uct_prior_even(u, node, map);
 	if (u->eye_eqex)
 		uct_prior_eye(u, node, map);
+	if (u->ko_eqex)
+		uct_prior_ko(u, node, map);
 	if (u->b19_eqex)
 		uct_prior_b19(u, node, map);
 	if (u->gp_eqex)
diff --git a/uct/uct.c b/uct/uct.c
index a035000..21650d3 100644
--- a/uct/uct.c
+++ b/uct/uct.c
@@ -599,6 +599,8 @@ uct_state_init(char *arg)
 				u->cfgd_eqex = atoi(optval);
 			} else if (!strcasecmp(optname, "prior_eye") && optval) {
 				u->eye_eqex = atoi(optval);
+			} else if (!strcasecmp(optname, "prior_ko") && optval) {
+				u->ko_eqex = atoi(optval);
 			} else if (!strcasecmp(optname, "amaf_prior") && optval) {
 				u->amaf_prior = atoi(optval);
 			} else if (!strcasecmp(optname, "threads") && optval) {
-- 
2.11.4.GIT