Re: [gnugo-devel] Proposed owl_determine_life() improvement

[bump]

> I'll post the revised patch if the regressions are promising in
> a few hours.

Here's the alternative patch and breakage. I won't be working on this
if Nando or anyone else wants to look at this example.

Dan

./regress.sh . owl.tst 
178 unexpected PASS!
212 unexpected FAIL: Correct '3 E16', got '0'
./regress.sh . nicklas4.tst 
805 unexpected FAIL: Correct 'C5|B4', got 'K7'
./regress.sh . trevor.tst 
340 unexpected FAIL: Correct '1 P9', got '1 Q9'
./regress.sh . semeai.tst 
32 unexpected FAIL: Correct 'ALIVE_IN_SEKI ALIVE_IN_SEKI B6', got 'DEAD ALIVE 
PASS'
./regress.sh . strategy4.tst 
179 unexpected PASS!
./regress.sh . handtalk.tst 
4 unexpected PASS!
./regress.sh . nngs2.tst 
110 unexpected FAIL: Correct 'B14|B13', got 'L16'
150 unexpected PASS!
./regress.sh . nngs3.tst 
320 unexpected PASS!
./regress.sh . nngs4.tst 
30 unexpected PASS!
./regress.sh . auto01.tst 
13 unexpected FAIL: Correct '1 (Q12|Q13)', got '0'

Index: engine/owl.c
===================================================================
RCS file: /cvsroot/gnugo/gnugo/engine/owl.c,v
retrieving revision 1.115
diff -u -r1.115 owl.c
--- engine/owl.c        23 Oct 2002 18:32:35 -0000      1.115
+++ engine/owl.c        4 Nov 2002 01:32:26 -0000
@@ -4589,8 +4589,10 @@
   int other = OTHER_COLOR(board[lunch]);
   int size;
   int libs[MAXLIBS];
+  int adjacent[MAXCHAIN];
+  int neighbors;
   int liberties;
-  int r;
+  int r, n;
 
   ASSERT1(IS_STONE(board[lunch]), lunch);
 
@@ -4618,7 +4620,22 @@
       }
     }
   }
-  
+  /* If the lunch adjoins a neighbor that is not part of the goal,
+   * munch to escape.
+   */
+  neighbors = chainlinks(lunch, adjacent);
+  for (n = 0; n < neighbors; n++)
+    if (!owl->goal[adjacent[n]]) {
+      liberties = findlib(adjacent[n], MAXLIBS, libs);
+      for (r = 0; r < liberties; r++) {
+       if (owl->escape_values[libs[r]] > 0) {
+         *min = 2;
+         *probable = 2;
+         *max = 2;
+         return;
+       }
+      }
+    }
   size = countstones(lunch);
   if (size > 6) {
     *min = 2;