commit 0ad2e864f63e77157815242b96faafdfae376dd8
parent b02fce00115ac597ba34fda128e43586f8710438
Author: Sebastiano Tronto <sebastiano@tronto.net>
Date: Thu, 17 Jul 2025 08:23:32 +0200
Comments for drslice
Diffstat:
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/src/solvers/coord/drslice.h b/src/solvers/coord/drslice.h
@@ -1,3 +1,16 @@
+/*
+TODO
+
+The pruning table for this coordinate shows some odd behavior, which
+is actually also present in nissy-classic: after completing depth 14,
+if the search is let run for higher depth, no more positions are found.
+This could be as simple as a small bug in the logic of the pruning table
+calculations - I may be assuming somewhere that I am never going to search
+for depths >= 15, since they are the highest possible value anyway -
+or some reason related to symmetry - are some cases actually impossible?
+In the worst case, it is a bug to be fixed, but I find it unlikely.
+*/
+
#define CLASSES_CP_16 2768
STATIC uint64_t coordinate_cp_coord(cube_t);
@@ -30,7 +43,6 @@ STATIC coord_t coordinate_drslice = {
.is_admissible = &solution_always_valid,
.is_solvable = &is_drslice_solvable,
.pruning_distribution = {
- /* TODO: copied from nissy-classic, to be verified */
[0] = 1,
[1] = 3,
[2] = 10,
@@ -46,10 +58,9 @@ STATIC coord_t coordinate_drslice = {
[12] = 18349792,
[13] = 32843350,
[14] = 34118883,
- [15] = 0, /* TODO: unknown, why does nissy-classic not have
- have this value? */
+ [15] = 17284701
},
- .pruning_max = 15, /* TODO - either 14 or 15 */
+ .pruning_max = 15,
.sym = {
.classes = CLASSES_CP_16,
.max = FACT_8,
