/* Find moves turning supposed territory into seki. This is not
* detected above since it either involves an ALIVE dragon adjacent to
* a CRITICAL dragon, or an ALIVE dragon whose eyespace can be invaded
* and turned into a seki.
*
* Currently we only search for tactically critical strings with
* dragon status dead, which are neighbors of only one opponent
* dragon, which is alive. Through semeai analysis we then determine
* whether such a string can in fact live in seki. Relevant testcases
* include gunnar:42 and gifu03:2.
*/
static void
find_moves_to_make_seki()
{
int str;
int defend_move;
int resulta, resultb;
for (str = BOARDMIN; str < BOARDMAX; str++) {
if (IS_STONE(board[str]) && is_worm_origin(str, str)
&& attack_and_defend(str, NULL, NULL, NULL, &defend_move)
&& dragon[str].status == DEAD
&& DRAGON2(str).hostile_neighbors == 1) {
int k;
int color = board[str];
int opponent = NO_MOVE;
int certain;
struct eyevalue reduced_genus;
for (k = 0; k < DRAGON2(str).neighbors; k++) {
opponent = dragon2[DRAGON2(str).adjacent[k]].origin;
if (board[opponent] != color)
break;
}
ASSERT1(opponent != NO_MOVE, opponent);
if (dragon[opponent].status != ALIVE)
continue;
/* FIXME: These heuristics are used for optimization. We don't
* want to call expensive semeai code if the opponent
* dragon has more than one eye elsewhere. However, the
* heuristics might still need improvement.
*/
compute_dragon_genus(opponent, &reduced_genus, str);
if (DRAGON2(opponent).moyo_size > 10 || min_eyes(&reduced_genus) > 1)
continue;
owl_analyze_semeai_after_move(defend_move, color, opponent, str,
&resulta, &resultb, NULL, 1, &certain, 0);
/* Do not trust uncertain results. In fact it should only take a
* few nodes to determine the semeai result, if it is a proper
* potential seki position.
*/
if (resultb != WIN && certain) {
int d = dragon[str].id;
DEBUG(DEBUG_SEMEAI, "Move to make seki at %1m (%1m vs %1m)\n",
defend_move, str, opponent);
dragon2[d].semeais++;
update_status(str, CRITICAL, CRITICAL);
dragon2[d].semeai_defense_point = defend_move;
dragon2[d].semeai_defense_certain = certain;
dragon2[d].semeai_defense_target = opponent;
/* We need to determine a proper attack move (the one that
* prevents seki). Currently we try the defense move first,
* and if it doesn't work -- all liberties of the string.
*/
owl_analyze_semeai_after_move(defend_move, OTHER_COLOR(color),
str, opponent, &resulta, NULL,
NULL, 1, NULL, 0);
if (resulta != WIN)
dragon2[d].semeai_attack_point = defend_move;
else {
int k;
int libs[MAXLIBS];
int liberties = findlib(str, MAXLIBS, libs);
for (k = 0; k < liberties; k++) {
owl_analyze_semeai_after_move(libs[k], OTHER_COLOR(color),
str, opponent, &resulta, NULL,
NULL, 1, NULL, 0);
if (resulta != WIN) {
dragon2[d].semeai_attack_point = libs[k];
break;
}
}
/* FIXME: What should we do if none of the tried attacks worked? */
if (k == liberties)
dragon2[d].semeai_attack_point = defend_move;
}
DEBUG(DEBUG_SEMEAI, "Move to prevent seki at %1m (%1m vs %1m)\n",
dragon2[d].semeai_attack_point, opponent, str);
dragon2[d].semeai_attack_certain = certain;
dragon2[d].semeai_attack_target = opponent;
}
}
}
}
/* Find moves turning supposed territory into seki. This is not
* detected above since it either involves an ALIVE dragon adjacent to
* a CRITICAL dragon, or an ALIVE dragon whose eyespace can be invaded
* and turned into a seki.
*
* Currently we only search for tactically critical strings with
* dragon status dead, which are neighbors of only one opponent
* dragon, which is alive. Through semeai analysis we then determine
* whether such a string can in fact live in seki. Relevant testcases
* include gunnar:42 and gifu03:2.
*/
static void
find_moves_to_make_seki()
{
int str;
int defend_move;
int resulta, resultb;
for (str = BOARDMIN; str < BOARDMAX; str++) {
if (IS_STONE(board[str]) && is_worm_origin(str, str)
&& attack_and_defend(str, NULL, NULL, NULL, &defend_move)
&& dragon[str].status == DEAD
&& DRAGON2(str).hostile_neighbors == 1) {
int k;
int color = board[str];
int opponent = NO_MOVE;
int certain;
struct eyevalue reduced_genus;
for (k = 0; k < DRAGON2(str).neighbors; k++) {
opponent = dragon2[DRAGON2(str).adjacent[k]].origin;
if (board[opponent] != color)
break;
}
ASSERT1(opponent != NO_MOVE, opponent);
if (dragon[opponent].status != ALIVE)
continue;
/* FIXME: These heuristics are used for optimization. We don't
* want to call expensive semeai code if the opponent
* dragon has more than one eye elsewhere. However, the
* heuristics might still need improvement.
*/
compute_dragon_genus(opponent, &reduced_genus, str);
if (min_eyes(&reduced_genus) > 1
|| DRAGON2(opponent).moyo_size > 10
|| DRAGON2(opponent).moyo_territorial_value > 2.999
|| DRAGON2(opponent).escape_route > 0
|| DRAGON2(str).escape_route > 0)
continue;
owl_analyze_semeai_after_move(defend_move, color, opponent, str,
&resulta, &resultb, NULL, 1, &certain, 0);
if (resultb == WIN) {
owl_analyze_semeai(str, opponent, &resultb, &resulta,
&defend_move, 1, &certain);
resulta = REVERSE_RESULT(resulta);
resultb = REVERSE_RESULT(resultb);
}
/* Do not trust uncertain results. In fact it should only take a
* few nodes to determine the semeai result, if it is a proper
* potential seki position.
*/
if (resultb != WIN && certain) {
int d = dragon[str].id;
DEBUG(DEBUG_SEMEAI, "Move to make seki at %1m (%1m vs %1m)\n",
defend_move, str, opponent);
dragon2[d].semeais++;
update_status(str, CRITICAL, CRITICAL);
dragon2[d].semeai_defense_code = REVERSE_RESULT(resultb);
dragon2[d].semeai_defense_point = defend_move;
dragon2[d].semeai_defense_certain = certain;
gg_assert(board[opponent] == OTHER_COLOR(board[dragon2[d].origin]));
dragon2[d].semeai_defense_target = opponent;
/* We need to determine a proper attack move (the one that
* prevents seki). Currently we try the defense move first,
* and if it doesn't work -- all liberties of the string.
*/
owl_analyze_semeai_after_move(defend_move, OTHER_COLOR(color),
str, opponent, &resulta, NULL,
NULL, 1, NULL, 0);
if (resulta != WIN) {
dragon2[d].semeai_attack_code = REVERSE_RESULT(resulta);
dragon2[d].semeai_attack_point = defend_move;
}
else {
int k;
int libs[MAXLIBS];
int liberties = findlib(str, MAXLIBS, libs);
for (k = 0; k < liberties; k++) {
owl_analyze_semeai_after_move(libs[k], OTHER_COLOR(color),
str, opponent, &resulta, NULL,
NULL, 1, NULL, 0);
if (resulta != WIN) {
dragon2[d].semeai_attack_code = REVERSE_RESULT(resulta);
dragon2[d].semeai_attack_point = libs[k];
break;
}
}
if (k == liberties) {
DEBUG(DEBUG_SEMEAI,
"No move to attack in semeai (%1m vs %1m), seki assumed.\n",
str, opponent);
dragon2[d].semeai_attack_code = 0;
dragon2[d].semeai_attack_point = NO_MOVE;
update_status(str, ALIVE, ALIVE_IN_SEKI);
}
}
DEBUG(DEBUG_SEMEAI, "Move to prevent seki at %1m (%1m vs %1m)\n",
dragon2[d].semeai_attack_point, opponent, str);
dragon2[d].semeai_attack_certain = certain;
dragon2[d].semeai_attack_target = opponent;
}
}
}
/* Now look for dead strings inside a single eyespace of a living dragon.
*
* FIXME: Clearly this loop should share most of its code with the
* one above. It would also be good to reimplement so that
* moves invading a previously empty single eyespace to make
* seki can be found.
*/
for (str = BOARDMIN; str < BOARDMAX; str++) {
if (IS_STONE(board[str]) && is_worm_origin(str, str)
&& !find_defense(str, NULL)
&& dragon[str].status == DEAD
&& DRAGON2(str).hostile_neighbors == 1) {
int k;
int color = board[str];
int opponent = NO_MOVE;
int certain;
struct eyevalue reduced_genus;
for (k = 0; k < DRAGON2(str).neighbors; k++) {
opponent = dragon2[DRAGON2(str).adjacent[k]].origin;
if (board[opponent] != color)
break;
}
ASSERT1(opponent != NO_MOVE, opponent);
if (dragon[opponent].status != ALIVE)
continue;
/* FIXME: These heuristics are used for optimization. We don't
* want to call expensive semeai code if the opponent
* dragon has more than one eye elsewhere. However, the
* heuristics might still need improvement.
*/
compute_dragon_genus(opponent, &reduced_genus, str);
if (DRAGON2(opponent).moyo_size > 10 || min_eyes(&reduced_genus) > 1)
continue;
owl_analyze_semeai(str, opponent, &resulta, &resultb,
&defend_move, 1, &certain);
/* Do not trust uncertain results. In fact it should only take a
* few nodes to determine the semeai result, if it is a proper
* potential seki position.
*/
if (resulta != 0 && certain) {
int d = dragon[str].id;
DEBUG(DEBUG_SEMEAI, "Move to make seki at %1m (%1m vs %1m)\n",
defend_move, str, opponent);
dragon2[d].semeais++;
update_status(str, CRITICAL, CRITICAL);
dragon2[d].semeai_defense_code = resulta;
dragon2[d].semeai_defense_point = defend_move;
dragon2[d].semeai_defense_certain = certain;
gg_assert(board[opponent] == OTHER_COLOR(board[dragon2[d].origin]));
dragon2[d].semeai_defense_target = opponent;
/* We need to determine a proper attack move (the one that
* prevents seki). Currently we try the defense move first,
* and if it doesn't work -- all liberties of the string.
*/
owl_analyze_semeai_after_move(defend_move, OTHER_COLOR(color),
str, opponent, &resulta, NULL,
NULL, 1, NULL, 0);
if (resulta != WIN) {
dragon2[d].semeai_attack_code = REVERSE_RESULT(resulta);
dragon2[d].semeai_attack_point = defend_move;
}
else {
int k;
int libs[MAXLIBS];
int liberties = findlib(str, MAXLIBS, libs);
for (k = 0; k < liberties; k++) {
owl_analyze_semeai_after_move(libs[k], OTHER_COLOR(color),
str, opponent, &resulta, NULL,
NULL, 1, NULL, 0);
if (resulta != WIN) {
dragon2[d].semeai_attack_code = REVERSE_RESULT(resulta);
dragon2[d].semeai_attack_point = libs[k];
break;
}
}
if (k == liberties) {
DEBUG(DEBUG_SEMEAI,
"No move to attack in semeai (%1m vs %1m), seki assumed.\n",
str, opponent);
dragon2[d].semeai_attack_code = 0;
dragon2[d].semeai_attack_point = NO_MOVE;
update_status(str, ALIVE, ALIVE_IN_SEKI);
}
}
DEBUG(DEBUG_SEMEAI, "Move to prevent seki at %1m (%1m vs %1m)\n",
dragon2[d].semeai_attack_point, opponent, str);
dragon2[d].semeai_attack_certain = certain;
dragon2[d].semeai_attack_target = opponent;
}
}
}
}