commit 82904137aff5a7de8b9aee55485c1b0217e0b2e6
parent c90781c8602bd2ff17270105c98277ac79665ac8
Author: Sebastiano Tronto <sebastiano@tronto.net>
Date: Fri, 8 Aug 2025 09:43:15 +0200
Added solver documentation
Diffstat:
2 files changed, 147 insertions(+), 1 deletion(-)
diff --git a/doc/solvers.md b/doc/solvers.md
@@ -0,0 +1,146 @@
+# Solvers
+
+This document contains a list cube solvers supported by this library.
+Some solvers require the cube to be in a certain state before they can
+be used - see below for details.
+
+## The H48 optimal solver
+
+An HTM-optimal solver using fully-symmetric pruning tables. For details
+about how this solver works, see [h48.md](./h48.md). For benchmarks see
+[benchmarks/benchmarks.md](../benchmarks/benchmarks.md).
+
+* Name: of the form `h8hXk2` for `X` from 0 to 11, or `h48h0k4`. The name
+ `optimal` is an alias for `h48h7k2`.
+* Requisites: none.
+* Moveset: HTM (all 18 basic moves).
+* Data size: 59MB for `h48h0k4`, from 115MB to 59GB for `h48hXk2`
+ (roughly 59MB + 2<sup>X</sup>*56MB).
+
+## Coordinate solvers
+
+Various solvers to solve different substeps, commonly used for Fewest
+Moves solving.
+
+The names start either with `coord_` or with `mcoord_`, and the last two
+letters denote a transformation to adjust the starting orientation. For
+example, `coord_EO_UR` solves the edge orientation on the RL axis.
+
+For simplicity and for compatibility with nissy-classic, some aliases
+are provided.
+
+### Edge orientation
+
+Solve the edge orientation on the FB axis. NISS can be used.
+
+* Name: `coord_EO_xx`, where `xx` denotes the rotation.
+ Provided aliases are:
+ * `eofb` for `coord_EO_UF` (EO on FB)
+ * `eorl` for `coord_EO_UR` (EO on RL)
+ * `eoud` for `coord_EO_FD` (EO on UD)
+* Requisites: none.
+* Moveset: HTM (all 18 basic moves). The ending quarter turns are
+ always clockwise.
+* Data size: 1.5KB.
+
+### Domino reduction
+
+Solve the domino reduction on the UD axis. NISS can be used.
+
+* Name: `coord_DR_xx`, where `xx` denotes the rotation.
+ Provided aliases are:
+ * `drud` for `coord_DR_UF` (DR on UD)
+ * `drrl` for `coord_DR_RF` (DR on RL)
+ * `drfb` for `coord_DR_FD` (DR on FB)
+* Requisites: none.
+* Moveset: HTM (all 18 basic moves). The ending quarter turns are
+ always clockwise.
+* Data size: 72MB.
+
+### Domino reduction from edge orientation
+
+Solve the domino reduction on UD from edge orientation on FB.
+NISS can be used.
+
+* Name: `coord_DREO_xx`, where `xx` denotes the rotation.
+ Provided aliases are:
+ * `drud-eofb` for `coord_DREO_UF` (DR on UD from EO on FB)
+ * `drrl-eofb` for `coord_DREO_RF` (DR on RL from EO on FB)
+ * `drud-eorl` for `coord_DREO_UR` (DR on UD from EO on RL)
+ * `drfb-eorl` for `coord_DREO_RU` (DR on FB from EO on RL)
+ * `drrl-eoud` for `coord_DREO_FR` (DR on RL from EO on UD)
+ * `drfb-eoud` for `coord_DREO_FD` (DR on FB from EO on UD)
+* Requisites: edge orientation must be solved on FB.
+* Moveset: {U, U', U2, D, D', D2, R2, L2, F2, B2}.
+ The ending quarter turns are always clockwise.
+* Data size: 91KB.
+
+### HTR from domino reduction
+
+Solve the half turn reduction from domino reduction on UD.
+NISS can be used.
+
+* Name: `coord_HTR_xx`, where `xx` denotes the rotation.
+ Provided aliases are:
+ * `htr-drud` for `coord_DR_UF` (HTR from DR on UD)
+ * `htr-drrl` for `coord_DR_LF` (HTR from DR on RL)
+ * `htr-drfb` for `coord_DR_BU` (HTR from DR on FB)
+* Requisites: domino reduction is solved on UD.
+* Moveset: {U, U', U2, D, R2, L2, F2, B2}. The ending quarter turns are
+ always clockwise. Moreover, solutions are filtered so that at most
+ one D move is used, and it will always appear before any U or U' move.
+ Solutions with consecutive U / U2 / U' / D moves are also filtered out.
+ This solver will produce therefore fewer solutions than nissy-classic.
+* Data size: 265KB.
+
+### Leave slice from domino reduction
+
+Solve all but the E-layer from domino reduction on UD.
+The E-layer centers may not be solved. NISS will not be used.
+
+* Name: `coord_DRSLICE_xx`, where `xx` denotes the rotation.
+ Provided aliases are:
+ * `drudslice` for `coord_DRSLICE_UF` (Leave slice from DR on UD)
+ * `drrlslice` for `coord_DRSLICE_LF` (Leave slice from DR on RL)
+ * `drfbslice` for `coord_DRSLICE_BU` (Leave slice from DR on FB)
+* Requisites: domino reduction is solved on UD.
+* Moveset: {U, U', U2, R2, L2, F2, B2}.
+* Data size: 54MB.
+
+### Solve all from domino reduction
+
+Solve the whole cube from domino reduction on UD.
+NISS will not be used.
+
+* Name: `coord_DRFIN_xx`, where `xx` denotes the rotation.
+ Provided aliases are:
+ * `drudfin` for `coord_DRSLICE_UF` (Solve from DR on UD)
+ * `drrlfin` for `coord_DRSLICE_LF` (Solve from DR on RL)
+ * `drfbfin` for `coord_DRSLICE_BU` (Solve from DR on FB)
+* Requisites: domino reduction is solved on UD.
+* Moveset: {U, U', U2, D, D', D2, R2, L2, F2, B2}.
+* Data size: 54MB.
+
+### Undocumented coordinate solvers
+
+There are some coordinate solvers that have not been listed above. These
+are generally not very useful on their own, but instead they are combined
+to produce some of the more complex coordinate solvers above.
+
+These solvers include:
+
+* `coord_CPEPE_xx`: solve the permutation of the corners and of the E-layer
+ edges. Requires DR to be solved on UD.
+* `coord_DRFINNOE_xx`: like the "leave slice" solver, but the U and D
+ layers are going to be adjusted so that centers are solved. We chose
+ to use `coord_DRSLICE_xx` as described above as it may produce shorter
+ solutions, and it is easier to filter out duplicates (solutions that
+ differ only by how they affect the E-layer).
+
+## Planned future solvers
+
+The following solvers are planned to be introduced in the future:
+
+* Finish from HTR
+* JZP / Axial reduction, from EO or direct
+* Finish / leave double slice from JZP
diff --git a/src/nissy.h b/src/nissy.h
@@ -346,7 +346,7 @@ Solve the given cube using the given solver and options.
Parameters:
cube - The cube to solver.
- solver - The name of the solver.
+ solver - The name of the solver. See doc/solvers.md for a list.
nissflag - The flags for NISS (linear, inverse, mixed, or
combinations; see the constants at the top of this file).
minmoves - The minimum number of moves for a solution.
