commit 7e9afaa14ca293a7e9d5a76af36d9a0aecbb031d
parent f987f5af492f2ac9d5aeebd351bcb49175556af2
Author: Sebastiano Tronto <sebastiano@tronto.net>
Date: Mon, 29 May 2023 01:10:09 +0200
Removed useless files
Diffstat:
6 files changed, 0 insertions(+), 1923 deletions(-)
diff --git a/src/cube.sync-conflict-20230524-181836-JOKKFPA.c b/src/cube.sync-conflict-20230524-181836-JOKKFPA.c
@@ -1,614 +0,0 @@
-/*
-# Cube representation, moves, transformations and indexing
-
-## String description
-
-The functions readcube() and writecube() use the following format.
-Each edge is represented by two letters denoting the sides it belongs to
-and one number denoting its orientation (0 oriented, 1 mis-oriented).
-Similarly, each corner is represented by three letters and a number
-(0 oriented, 1 twisted clockwise, 2 twisted counter-clockwise).
-Edge orientation is relative to the F / B axis, corner orientation is
-relative to the U / D axis.
-
-The correct order of the pieces is the same as that defined in the
-section "Internal cube representation", except that pieces are read
-left-to-right. Pieces are divided by slices, so the ordering is not the
-most intuitive, but it is more convenient for the internal representation.
-
-Whitespaces between pieces are ignored when reading the cube, and a
-single whitespace character is added between pieces when writing.
-
-For example, the solved cube looks like this:
-
-UF0 UB0 DB0 DF0 UR0 UL0 DL0 DR0 FR0 FL0 BL0 BR0 UFR0 UBL0 DFL0 DBR0 UFL0 UBR0 DFR0 DBL0
-
-The cube after the moves R'U'F looks like this:
-
-FL1 BR0 DB0 UR1 UF0 UB0 DL0 FR0 UL1 DF1 BL0 DR0 UBL1 DBR1 UFR2 DFR2 DFL2 UBL2 UFL2 DBL0
-
-More formats might be supported in the future.
-
-## Internal cube representation
-
-The cube_t data structure implemented in this file is designed to
-efficiently perform common operations on a 3x3x3 Rubik's cube when
-solving it with an iterative-deepening DFS search. It is not the most
-general, complete, easy to read or compact one. Since the cube can
-be trivially reoriented before the search, we only encode permutations
-of the cube that keep the center pieces in a fixed position (that is,
-we do not encode the position of the centers).
-
-The cube state is encoded in two 64-bit integers, one for edges and one
-for centers. We explain how edges are encoded first, and the highlight
-the few differences with corners afterwards.
-
-For encoding edges, only the 60 least-significant bits are used. Each
-edge described by 5 bits. The position of a 5-bit block in the 64-bit
-integer determine the position of the edge piece in the cube, according
-to the following table (least-significant bits on the right):
-
-55-59 50-54 45-49 40-44 35-39 30-34 25-29 20-24 15-19 10-14 5-9 0-4
- BR BL FL FR DR DL UL UR DF DB UB UF
-ossee ossee ossee ossee ossee ossee ossee ossee ossee ossee ossee ossee
-
-For each edge, the 4 least-significant bits ('ssee' in the table)
-determine the piece. The two bits marked with 'ss' determine the internal
-slice the piece belongs to, i.e. they are either '00' for M, '01' for
-S or '10' for E. The other two bits (marked with 'ee') determine the
-actual edge piece among the 4 in the same slice, and they are assigned
-somewhat arbitarily. Using this representation and the ordering defined
-in the table above, the edges are correctly permuted when these 4 bits
-for each represent the numbers 0 to 11 in the correct order.
-
-The last bit determines the orientation. The orientation of an edge
-depends on its position, and it is defined being 0 if the edge can be
-moved to its place in the solved orientation by permutations in the
-subgroup <U, D, R, L, F2, B2>.
-
-Corners are encoded in the 48 least-significant bits, and are described
-by 6 bits each, their position being defined by the following table:
-
- 35-39 30-34 25-29 20-24 15-19 10-14 5-9 0-4
- DBL DFL UBR UFL DBR DFL UBL UFR
-oooxcc oooxcc oooxcc oooxcc oooxcc oooxcc oooxcc oooxcc
-
-The bit marked with an 'x' describes the axis the corner belongs to.
-The 0 axis consists of the corners UFR, UBL, DFL and DBR, and the other
-four corners form the axis marked with 1. Then two bits are needed to
-identify the corner among the four of the same axis. The last three bits
-determine the orientation, where one corner is defined to be oriented
-(marked with '000') if its top or bottom sticker faces the top or bottom
-side. A corner a clockwise turn away from being oriented, thus requiring
-a counter-clockwise turn to be oriented correctly, is marked with '001',
-and a corner a counter-clockwise turn away is marked with '010'. The most
-significant bit is not used to determine the corner orientation, but it
-must always be set to '0' to simplify the moving operations (see below).
-
-## Basic moves
-
-The 18 basic moves of the cube could be performed by applying a suitable
-general permutation (see below), but they have instead been manually
-implemented with a few simple operations each, to improve performance.
-
-For each move we first permute the pieces. This amounts to shifting
-around 4 blocks of bits for edges and 4 for corners. Since in some cases
-adjacent pieces on the cube are also adjacent in the bit representation we
-use, we can save some operations by shifting multiple blocks together.
-For example, for the move U for edges we shift a block of 15 bits 5
-positions to the left and a block of 5 bits 15 positions to the right.
-
-There are some moves that change the orientation of the pieces. Namely,
-the moves F, F', B and B' change the orientation of the edges and those
-moves as well as R, R', L and L' change the orientation of the corners.
-Edge orientation is easy to address: we simply xor the edge representation
-by a bit mask with zeroes everywhere except for the 4 edges that need
-to be flipped (i.e. the ones on the twisted face).
-
-Corner orientation is harder to reproduce efficiently working only with
-bitwise operations, as it involves performing operations modulo 3.
-However, with the help of the extra bit we reserved, we are able to
-do this using only two additions and 3 bitwise operations, without
-any multiplication, division or modulo operation. The trick is
-to use the following formula to sum two numbers x, y in {0,1,2}:
-
- ((x+y) + (x+y+1)/4) % 4
-
-The thrid bit is needed because x+y and x+y+1 can exceed 3.
-See below (in the code) for the details.
-
-## Inverting the cube
-
-TODO
-
-## Transformations (conjugations by full-cube rotations)
-
-TODO
-
-## Indexing
-
-TODO - subgroup description etc
-
-Ideas for pruning (for another file?):
-- Use corner separation + CO as main coordinate (~150k states)
- - for huge tables, htr corners can be used (6 times larger)
-- Symmetry table, one entry or each main coordinate value with the
- following info:
- - index of the corresponding main symcoord (13 bits)
- - transtorep (6 bits)
- - base value for pruning table (5 bits, probably 4)
- - pruning value for only main coord, i.e. fallback (4 bits)
-- To get a full coord for the cube:
- - get first coord c, get the transtorep
- - transform edges with transtorep
- - get second coordinate e
- - return c * MAXE + e
- - This is still too big, so divide by a power of 2 to get the hashed index
- - second coordinate: ep always, + varible number of eo bit (0 to 11)
-- Generate table:
- - first probe for base value:
- - solve coord using fallback table for pruning for 10k random states or so
- - loop over all possible values (even if going for smaller table)
- - with inverse-index strategy or what?
- - use 1 bit per entry (more than base value or not)
-*/
-
-#include <stdbool.h>
-#include <stdint.h>
-#include <string.h>
-
-#ifdef DEBUG
-#include <stdio.h>
-#endif
-
-#include "cube.h"
-
-#define _error 0xFFFFFFFF
-
-#define _esize 5ULL
-#define _eoblock 0x10ULL /* 10000 */
-#define _epblock 0x0FULL /* 01111 */
-#define _eblock 0x1FULL /* 11111 */
-
-#define _csize 6ULL
-#define _coblock 0x18ULL /* 011000 */
-#define _cpblock 0x07ULL /* 000111 */
-#define _cblock 0x3FULL /* 111111 */
-
-#define _edge_uf 0ULL /* 00 00 */
-#define _edge_ub 1ULL /* 00 01 */
-#define _edge_db 2ULL /* 00 10 */
-#define _edge_df 3ULL /* 00 11 */
-#define _edge_ur 4ULL /* 01 00 */
-#define _edge_ul 5ULL /* 01 01 */
-#define _edge_dl 6ULL /* 01 10 */
-#define _edge_dr 7ULL /* 01 11 */
-#define _edge_fr 8ULL /* 10 00 */
-#define _edge_fl 9ULL /* 10 01 */
-#define _edge_bl 10ULL /* 10 10 */
-#define _edge_br 11ULL /* 10 11 */
-
-#define _corner_ufr 0ULL /* 0 00 */
-#define _corner_ubl 1ULL /* 0 01 */
-#define _corner_dfl 2ULL /* 0 10 */
-#define _corner_dbr 3ULL /* 0 11 */
-#define _corner_ufl 4ULL /* 1 00 */
-#define _corner_ubr 5ULL /* 1 01 */
-#define _corner_dfr 6ULL /* 1 10 */
-#define _corner_dbl 7ULL /* 1 11 */
-
-#define ESHIFT(i) ((i) * _esize)
-#define EOSHIFT(i) (4ULL + (i) * _esize)
-#define EMASK(i) (_eblock << ESHIFT(i))
-#define EOMASK(i) (_eoblock << ESHIFT(i))
-#define EPMASK(i) (_epblock << ESHIFT(i))
-#define ESOLVED(ee) (_edge_##ee << (_edge_##ee * _esize))
-#define EDGEAT(e, i) (((e) & EMASK(i)) >> ESHIFT(i))
-#define EOAT(e, i) (((e) & EOMASK(i)) >> EOSHIFT(i))
-#define EPAT(e, i) (((e) & EPMASK(i)) >> ESHIFT(i))
-
-#define CSHIFT(i) ((i) * _csize)
-#define COSHIFT(i) (3ULL + (i) * _csize)
-#define CMASK(i) (_cblock << CSHIFT(i))
-#define COMASK(i) (_coblock << CSHIFT(i))
-#define CPMASK(i) (_cpblock << CSHIFT(i))
-#define CSOLVED(ccc) (_corner_##ccc << (_corner_##ccc * _csize))
-#define CORNERAT(c, i) (((c) & CMASK(i)) >> CSHIFT(i))
-#define COAT(c, i) (((c) & COMASK(i)) >> COSHIFT(i))
-#define CPAT(c, i) (((c) & CPMASK(i)) >> CSHIFT(i))
-
-#define _emask_u (EMASK(uf) | EMASK(ul) | EMASK(ub) | EMASK(ur))
-#define _emask_d (EMASK(df) | EMASK(dl) | EMASK(db) | EMASK(dr))
-#define _emask_r (EMASK(ur) | EMASK(dr) | EMASK(fr) | EMASK(br))
-#define _emask_l (EMASK(ul) | EMASK(dl) | EMASK(fl) | EMASK(bl))
-#define _emask_f (EMASK(uf) | EMASK(df) | EMASK(fr) | EMASK(fl))
-#define _emask_b (EMASK(ub) | EMASK(db) | EMASK(br) | EMASK(bl))
-
-#define _cmask_u (CMASK(ufr) | CMASK(ufl) | CMASK(ubl) | CMASK(ubr))
-#define _cmask_d (CMASK(dfr) | CMASK(dfl) | CMASK(dbl) | CMASK(dbr))
-#define _cmask_r (CMASK(ufr) | CMASK(dfr) | CMASK(ubr) | CMASK(dbr))
-#define _cmask_l (CMASK(ufl) | CMASK(dfl) | CMASK(ubl) | CMASK(dbl))
-#define _cmask_f (CMASK(ufr) | CMASK(ufl) | CMASK(dfr) | CMASK(dfl))
-#define _cmask_b (CMASK(ubr) | CMASK(ubl) | CMASK(dbr) | CMASK(dbl))
-
-#define _eomask (EOMASK(uf) | EOMASK(ul) | EOMASK(ub) | EOMASK(ur) \
- EOMASK(df) | EOMASK(dl) | EOMASK(db) | EOMASK(dr) \
- EOMASK(fr) | EOMASK(fl) | EOMASK(bl) | EOMASK(br))
-#define _comask (COMASK(ufr) | COMASK(ufl) | COMASK(ubl) | COMASK(ubr) \
- COMASK(dfr) | COMASK(dfl) | COMASK(dbl) | COMASK(dbr))
-
-static uint64_t permsign(uint64_t *, int);
-static uint64_t readep(char *);
-static uint64_t readeo(char *);
-static uint64_t readcp(char *);
-static uint64_t readco(char *);
-static uint64_t readmove(char);
-static uint64_t readmodifier(char);
-
-static char *edgestr[] = {
- [_edge_uf] = "UF",
- [_edge_ub] = "UB",
- [_edge_db] = "DB",
- [_edge_df] = "DF",
- [_edge_ur] = "UR",
- [_edge_ul] = "UL",
- [_edge_dl] = "DL",
- [_edge_dr] = "DR",
- [_edge_fr] = "FR",
- [_edge_fl] = "FL",
- [_edge_bl] = "BL",
- [_edge_br] = "BR"
-};
-static char *cornerstr[] = {
- [_corner_ufr] = "UFR",
- [_corner_ubl] = "UBL",
- [_corner_dfl] = "DFL",
- [_corner_dbr] = "DBR",
- [_corner_ufl] = "UFL",
- [_corner_ubr] = "UBR",
- [_corner_dfr] = "DFR",
- [_corner_dbl] = "DBL"
-};
-static char *movestr[] = {
- [U] = "U", [U2] = "U2", [U3] = "U'",
- [D] = "D", [D2] = "D2", [D3] = "D'",
- [R] = "R", [R2] = "R2", [R3] = "R'",
- [L] = "L", [L2] = "L2", [L3] = "L'",
- [F] = "F", [F2] = "F2", [F3] = "F'",
- [B] = "B", [B2] = "B2", [B3] = "B'",
-};
-
-cube_t solvedcube = {
- .e = ESOLVED(uf) | ESOLVED(ul) | ESOLVED(ub) | ESOLVED(ur) |
- ESOLVED(df) | ESOLVED(dl) | ESOLVED(db) | ESOLVED(dr) |
- ESOLVED(fr) | ESOLVED(fl) | ESOLVED(bl) | ESOLVED(br),
- .c = CSOLVED(ufr) | CSOLVED(ufl) | CSOLVED(ubl) | CSOLVED(ubr) |
- CSOLVED(dfr) | CSOLVED(dfl) | CSOLVED(dbl) | CSOLVED(dbr),
-};
-cube_t errorcube = { .e = _error, .c = _error };
-
-
-static uint64_t
-permsign(uint64_t *a, int n)
-{
- int i, j;
- uint64_t ret;
-
- ret = 0;
-
- for (i = 0; i < n; i++)
- for (j = i+1; j < n; j++)
- ret += a[i] > a[j] ? 1 : 0;
-
- return ret % 2;
-}
-
-bool
-isconsistent(cube_t cube)
-{
- uint64_t p[12], sum;
- bool found[12];
- int i;
-
- sum = 0;
-
- /* Check for EP consistency */
- for (i = 0; i < 12; i++)
- found[i] = false;
- for (i = 0; i < 12; i++) {
- p[i] = EPAT(cube.e, i);
- found[p[i]] = true;
- }
- for (i = 0; i < 12; i++)
- if (!found[i])
- return false;
- sum = permsign(p, 12);
-
- /* Check for CP consistency */
- for (i = 0; i < 8; i++)
- found[i] = false;
- for (i = 0; i < 8; i++) {
- p[i] = CPAT(cube.c, i);
- found[p[i]] = true;
- }
- for (i = 0; i < 8; i++)
- if (!found[i])
- return false;
- sum += permsign(p, 8);
-
- /* Check permutation parity */
- if (sum % 2 != 0)
- return false;
-
- /* Check for EO parity */
- for (i = 0, sum = 0; i < 12; i++)
- sum += EOAT(cube.e, i);
- if (sum % 2 != 0)
- return false;
-
- /* Check for CO parity */
- for (i = 0, sum = 0; i < 8; i++)
- sum += COAT(cube.c, i);
- if (sum % 3 != 0)
- return false;
-
- /* Check that CO extra bit is zero */
- for (i = 0; i < 8; i++)
- if (cube.c & (1ULL << (5 + i * _csize)))
- return false;
-
- return true;
-}
-
-bool
-issolved(cube_t cube)
-{
- return cube.c == solvedcube.c && cube.e == solvedcube.e;
-}
-
-
-static uint64_t
-readep(char *str)
-{
- if (!strncmp(str, "UF", 2))
- return _edge_uf;
- if (!strncmp(str, "UL", 2))
- return _edge_ul;
- if (!strncmp(str, "UB", 2))
- return _edge_ub;
- if (!strncmp(str, "UR", 2))
- return _edge_ur;
- if (!strncmp(str, "DF", 2))
- return _edge_df;
- if (!strncmp(str, "DL", 2))
- return _edge_dl;
- if (!strncmp(str, "DB", 2))
- return _edge_db;
- if (!strncmp(str, "DR", 2))
- return _edge_dr;
- if (!strncmp(str, "FR", 2))
- return _edge_fr;
- if (!strncmp(str, "FL", 2))
- return _edge_fl;
- if (!strncmp(str, "BL", 2))
- return _edge_bl;
- if (!strncmp(str, "BR", 2))
- return _edge_br;
-
- return _error;
-}
-
-static uint64_t
-readeo(char *str)
-{
- if (*str == '0')
- return 0ULL;
- if (*str == '1')
- return 1ULL;
-
- return _error;
-}
-
-static uint64_t
-readcp(char *str)
-{
- if (!strncmp(str, "UFR", 3) || !strncmp(str, "URF", 3))
- return _corner_ufr;
- if (!strncmp(str, "UFL", 3) || !strncmp(str, "ULF", 3))
- return _corner_ufl;
- if (!strncmp(str, "UBL", 3) || !strncmp(str, "ULB", 3))
- return _corner_ubl;
- if (!strncmp(str, "UBR", 3) || !strncmp(str, "URB", 3))
- return _corner_ubr;
- if (!strncmp(str, "DFR", 3) || !strncmp(str, "DRF", 3))
- return _corner_dfr;
- if (!strncmp(str, "DFL", 3) || !strncmp(str, "DLF", 3))
- return _corner_dfl;
- if (!strncmp(str, "DBL", 3) || !strncmp(str, "DLB", 3))
- return _corner_dbl;
- if (!strncmp(str, "DBR", 3) || !strncmp(str, "DRB", 3))
- return _corner_dbr;
-
- return _error;
-}
-
-static uint64_t
-readco(char *str)
-{
- if (*str == '0')
- return 0ULL;
- if (*str == '1')
- return 1ULL;
- if (*str == '2')
- return 2ULL;
-
- return _error;
-}
-
-cube_t
-readcube(char *buf)
-{
- int i;
- uint64_t piece, orient;
- cube_t ret = {0};
- char *b = buf;
-
- for (i = 0; i < 12; i++) {
- while (*b == ' ' || *b == '\t' || *b == '\n')
- b++;
- if ((piece = readep(b)) == _error)
- goto readcube_error;
- b += 2;
- if ((orient = readeo(b)) == _error)
- goto readcube_error;
- b++;
- ret.e |= (piece << ESHIFT(i)) | (orient << EOSHIFT(i));
- }
- for (i = 0; i < 8; i++) {
- while (*b == ' ' || *b == '\t' || *b == '\n')
- b++;
- if ((piece = readcp(b)) == _error)
- goto readcube_error;
- b += 3;
- if ((orient = readco(b)) == _error)
- goto readcube_error;
- b++;
- ret.c |= (piece << CSHIFT(i)) | (orient << COSHIFT(i));
- }
-
- return ret;
-
-readcube_error:
- return errorcube;
-}
-
-void
-writecube(cube_t cube, char *buf)
-{
- char *errormsg;
- uint64_t piece;
- size_t len;
- int i;
-
- if (!isconsistent(cube)) {
- errormsg = "ERROR: cannot write inconsistent cube";
- goto writecube_error;
- }
-
- for (i = 0; i < 12; i++) {
- piece = EPAT(cube.e, i);
- buf[4*i ] = edgestr[piece][0];
- buf[4*i + 1] = edgestr[piece][1];
- buf[4*i + 2] = EOAT(cube.e, i) + '0';
- buf[4*i + 3] = ' ';
- }
- for (i = 0; i < 8; i++) {
- piece = CPAT(cube.c, i);
- buf[48 + 5*i ] = cornerstr[piece][0];
- buf[48 + 5*i + 1] = cornerstr[piece][1];
- buf[48 + 5*i + 2] = cornerstr[piece][2];
- buf[48 + 5*i + 3] = COAT(cube.c, i) + '0';
- buf[48 + 5*i + 4] = ' ';
- }
-
- buf[48+39] = '\0';
-
- return;
-
-writecube_error:
- len = strlen(errormsg);
- strcpy(buf, errormsg);
- buf[len] = '\n';
- buf[len+1] = '\0';
-}
-
-
-static uint64_t
-readmove(char c)
-{
- switch (c) {
- case 'U':
- return U;
- case 'D':
- return D;
- case 'R':
- return R;
- case 'L':
- return L;
- case 'F':
- return F;
- case 'B':
- return B;
- default:
- return _error;
- }
-}
-
-static uint64_t
-readmodifier(char c)
-{
- switch (c) {
- case '1': /* Fallthrough */
- case '2': /* Fallthrough */
- case '3':
- return c - '0' - 1;
- case '\'':
- return 2;
- default:
- return 0;
- }
-}
-
-int
-readmoves(char *buf, move_t *m)
-{
- int n;
- uint64_t r;
- char *b;
-
- for (b = buf, n = 0; *b != '\0'; b++) {
- while (*b == ' ' || *b == '\t' || *b == '\n')
- b++;
- if ((r = readmove(*b)) == _error)
- return -1;
- m[n] = (move_t)r;
- if ((r = readmodifier(*(b+1))) != 0) {
- b++;
- m[n] += r;
- }
- n++;
- }
-
- return n;
-}
-
-void
-writemoves(move_t *m, int n, char *buf)
-{
- int i;
- char *b, *s;
-
- for (i = 0, b = buf; i < n; i++, b++) {
- s = movestr[m[i]];
- strcpy(b, s);
- b += strlen(s);
- *b = ' ';
- }
- *b = '\0';
-}
-
-
-cube_t
-move(move_t m, cube_t c)
-{
- /* TODO - not implemented yet */
-
- cube_t ret = {0};
-
- switch (m) {
- case U:
- return ret;
- default:
- return ret;
- }
-}
diff --git a/src/cube.sync-conflict-20230524-181836-JOKKFPA.h b/src/cube.sync-conflict-20230524-181836-JOKKFPA.h
@@ -1,27 +0,0 @@
-typedef enum {
- U, U2, U3, D, D2, D3,
- R, R2, R3, L, L2, L3,
- F, F2, F3, B, B2, B3
-} move_t;
-typedef struct {
- uint64_t e;
- uint64_t c;
-} cube_t;
-
-extern cube_t solvedcube;
-extern cube_t errorcube;
-
-bool isconsistent(cube_t);
-bool issolved(cube_t);
-
-cube_t readcube(char *);
-void writecube(cube_t, char *);
-
-int readmoves(char *, move_t *);
-void writemoves(move_t *, int, char *);
-
-/*
-cube_t move(move_t, cube_t);
-cube_t inverse(cube_t);
-
-*/
diff --git a/src/cube.sync-conflict-20230524-182143-JOKKFPA.c b/src/cube.sync-conflict-20230524-182143-JOKKFPA.c
@@ -1,614 +0,0 @@
-/*
-# Cube representation, moves, transformations and indexing
-
-## String description
-
-The functions readcube() and writecube() use the following format.
-Each edge is represented by two letters denoting the sides it belongs to
-and one number denoting its orientation (0 oriented, 1 mis-oriented).
-Similarly, each corner is represented by three letters and a number
-(0 oriented, 1 twisted clockwise, 2 twisted counter-clockwise).
-Edge orientation is relative to the F / B axis, corner orientation is
-relative to the U / D axis.
-
-The correct order of the pieces is the same as that defined in the
-section "Internal cube representation", except that pieces are read
-left-to-right. Pieces are divided by slices, so the ordering is not the
-most intuitive, but it is more convenient for the internal representation.
-
-Whitespaces between pieces are ignored when reading the cube, and a
-single whitespace character is added between pieces when writing.
-
-For example, the solved cube looks like this:
-
-UF0 UB0 DB0 DF0 UR0 UL0 DL0 DR0 FR0 FL0 BL0 BR0 UFR0 UBL0 DFL0 DBR0 UFL0 UBR0 DFR0 DBL0
-
-The cube after the moves R'U'F looks like this:
-
-FL1 BR0 DB0 UR1 UF0 UB0 DL0 FR0 UL1 DF1 BL0 DR0 UBL1 DBR1 UFR2 DFR2 DFL2 UBL2 UFL2 DBL0
-
-More formats might be supported in the future.
-
-## Internal cube representation
-
-The cube_t data structure implemented in this file is designed to
-efficiently perform common operations on a 3x3x3 Rubik's cube when
-solving it with an iterative-deepening DFS search. It is not the most
-general, complete, easy to read or compact one. Since the cube can
-be trivially reoriented before the search, we only encode permutations
-of the cube that keep the center pieces in a fixed position (that is,
-we do not encode the position of the centers).
-
-The cube state is encoded in two 64-bit integers, one for edges and one
-for centers. We explain how edges are encoded first, and the highlight
-the few differences with corners afterwards.
-
-For encoding edges, only the 60 least-significant bits are used. Each
-edge described by 5 bits. The position of a 5-bit block in the 64-bit
-integer determine the position of the edge piece in the cube, according
-to the following table (least-significant bits on the right):
-
-55-59 50-54 45-49 40-44 35-39 30-34 25-29 20-24 15-19 10-14 5-9 0-4
- BR BL FL FR DR DL UL UR DF DB UB UF
-ossee ossee ossee ossee ossee ossee ossee ossee ossee ossee ossee ossee
-
-For each edge, the 4 least-significant bits ('ssee' in the table)
-determine the piece. The two bits marked with 'ss' determine the internal
-slice the piece belongs to, i.e. they are either '00' for M, '01' for
-S or '10' for E. The other two bits (marked with 'ee') determine the
-actual edge piece among the 4 in the same slice, and they are assigned
-somewhat arbitarily. Using this representation and the ordering defined
-in the table above, the edges are correctly permuted when these 4 bits
-for each represent the numbers 0 to 11 in the correct order.
-
-The last bit determines the orientation. The orientation of an edge
-depends on its position, and it is defined being 0 if the edge can be
-moved to its place in the solved orientation by permutations in the
-subgroup <U, D, R, L, F2, B2>.
-
-Corners are encoded in the 48 least-significant bits, and are described
-by 6 bits each, their position being defined by the following table:
-
- 35-39 30-34 25-29 20-24 15-19 10-14 5-9 0-4
- DBL DFL UBR UFL DBR DFL UBL UFR
-oooxcc oooxcc oooxcc oooxcc oooxcc oooxcc oooxcc oooxcc
-
-The bit marked with an 'x' describes the axis the corner belongs to.
-The 0 axis consists of the corners UFR, UBL, DFL and DBR, and the other
-four corners form the axis marked with 1. Then two bits are needed to
-identify the corner among the four of the same axis. The last three bits
-determine the orientation, where one corner is defined to be oriented
-(marked with '000') if its top or bottom sticker faces the top or bottom
-side. A corner a clockwise turn away from being oriented, thus requiring
-a counter-clockwise turn to be oriented correctly, is marked with '001',
-and a corner a counter-clockwise turn away is marked with '010'. The most
-significant bit is not used to determine the corner orientation, but it
-must always be set to '0' to simplify the moving operations (see below).
-
-## Basic moves
-
-The 18 basic moves of the cube could be performed by applying a suitable
-general permutation (see below), but they have instead been manually
-implemented with a few simple operations each, to improve performance.
-
-For each move we first permute the pieces. This amounts to shifting
-around 4 blocks of bits for edges and 4 for corners. Since in some cases
-adjacent pieces on the cube are also adjacent in the bit representation we
-use, we can save some operations by shifting multiple blocks together.
-For example, for the move U for edges we shift a block of 15 bits 5
-positions to the left and a block of 5 bits 15 positions to the right.
-
-There are some moves that change the orientation of the pieces. Namely,
-the moves F, F', B and B' change the orientation of the edges and those
-moves as well as R, R', L and L' change the orientation of the corners.
-Edge orientation is easy to address: we simply xor the edge representation
-by a bit mask with zeroes everywhere except for the 4 edges that need
-to be flipped (i.e. the ones on the twisted face).
-
-Corner orientation is harder to reproduce efficiently working only with
-bitwise operations, as it involves performing operations modulo 3.
-However, with the help of the extra bit we reserved, we are able to
-do this using only two additions and 3 bitwise operations, without
-any multiplication, division or modulo operation. The trick is
-to use the following formula to sum two numbers x, y in {0,1,2}:
-
- ((x+y) + (x+y+1)/4) % 4
-
-The thrid bit is needed because x+y and x+y+1 can exceed 3.
-See below (in the code) for the details.
-
-## Inverting the cube
-
-TODO
-
-## Transformations (conjugations by full-cube rotations)
-
-TODO
-
-## Indexing
-
-TODO - subgroup description etc
-
-Ideas for pruning (for another file?):
-- Use corner separation + CO as main coordinate (~150k states)
- - for huge tables, htr corners can be used (6 times larger)
-- Symmetry table, one entry or each main coordinate value with the
- following info:
- - index of the corresponding main symcoord (13 bits)
- - transtorep (6 bits)
- - base value for pruning table (5 bits, probably 4)
- - pruning value for only main coord, i.e. fallback (4 bits)
-- To get a full coord for the cube:
- - get first coord c, get the transtorep
- - transform edges with transtorep
- - get second coordinate e
- - return c * MAXE + e
- - This is still too big, so divide by a power of 2 to get the hashed index
- - second coordinate: ep always, + varible number of eo bit (0 to 11)
-- Generate table:
- - first probe for base value:
- - solve coord using fallback table for pruning for 10k random states or so
- - loop over all possible values (even if going for smaller table)
- - with inverse-index strategy or what?
- - use 1 bit per entry (more than base value or not)
-*/
-
-#include <stdbool.h>
-#include <stdint.h>
-#include <string.h>
-
-#ifdef DEBUG
-#include <stdio.h>
-#endif
-
-#include "cube.h"
-
-#define _error 0xFFFFFFFF
-
-#define _esize 5ULL
-#define _eoblock 0x10ULL /* 10000 */
-#define _epblock 0x0FULL /* 01111 */
-#define _eblock 0x1FULL /* 11111 */
-
-#define _csize 6ULL
-#define _coblock 0x18ULL /* 011000 */
-#define _cpblock 0x07ULL /* 000111 */
-#define _cblock 0x3FULL /* 111111 */
-
-#define _edge_uf 0ULL /* 00 00 */
-#define _edge_ub 1ULL /* 00 01 */
-#define _edge_db 2ULL /* 00 10 */
-#define _edge_df 3ULL /* 00 11 */
-#define _edge_ur 4ULL /* 01 00 */
-#define _edge_ul 5ULL /* 01 01 */
-#define _edge_dl 6ULL /* 01 10 */
-#define _edge_dr 7ULL /* 01 11 */
-#define _edge_fr 8ULL /* 10 00 */
-#define _edge_fl 9ULL /* 10 01 */
-#define _edge_bl 10ULL /* 10 10 */
-#define _edge_br 11ULL /* 10 11 */
-
-#define _corner_ufr 0ULL /* 0 00 */
-#define _corner_ubl 1ULL /* 0 01 */
-#define _corner_dfl 2ULL /* 0 10 */
-#define _corner_dbr 3ULL /* 0 11 */
-#define _corner_ufl 4ULL /* 1 00 */
-#define _corner_ubr 5ULL /* 1 01 */
-#define _corner_dfr 6ULL /* 1 10 */
-#define _corner_dbl 7ULL /* 1 11 */
-
-#define ESHIFT(i) ((i) * _esize)
-#define EOSHIFT(i) (4ULL + (i) * _esize)
-#define EMASK(i) (_eblock << ESHIFT(i))
-#define EOMASK(i) (_eoblock << ESHIFT(i))
-#define EPMASK(i) (_epblock << ESHIFT(i))
-#define ESOLVED(ee) (_edge_##ee << (_edge_##ee * _esize))
-#define EDGEAT(e, i) (((e) & EMASK(i)) >> ESHIFT(i))
-#define EOAT(e, i) (((e) & EOMASK(i)) >> EOSHIFT(i))
-#define EPAT(e, i) (((e) & EPMASK(i)) >> ESHIFT(i))
-
-#define CSHIFT(i) ((i) * _csize)
-#define COSHIFT(i) (3ULL + (i) * _csize)
-#define CMASK(i) (_cblock << CSHIFT(i))
-#define COMASK(i) (_coblock << CSHIFT(i))
-#define CPMASK(i) (_cpblock << CSHIFT(i))
-#define CSOLVED(ccc) (_corner_##ccc << (_corner_##ccc * _csize))
-#define CORNERAT(c, i) (((c) & CMASK(i)) >> CSHIFT(i))
-#define COAT(c, i) (((c) & COMASK(i)) >> COSHIFT(i))
-#define CPAT(c, i) (((c) & CPMASK(i)) >> CSHIFT(i))
-
-#define _emask_u (EMASK(uf) | EMASK(ul) | EMASK(ub) | EMASK(ur))
-#define _emask_d (EMASK(df) | EMASK(dl) | EMASK(db) | EMASK(dr))
-#define _emask_r (EMASK(ur) | EMASK(dr) | EMASK(fr) | EMASK(br))
-#define _emask_l (EMASK(ul) | EMASK(dl) | EMASK(fl) | EMASK(bl))
-#define _emask_f (EMASK(uf) | EMASK(df) | EMASK(fr) | EMASK(fl))
-#define _emask_b (EMASK(ub) | EMASK(db) | EMASK(br) | EMASK(bl))
-
-#define _cmask_u (CMASK(ufr) | CMASK(ufl) | CMASK(ubl) | CMASK(ubr))
-#define _cmask_d (CMASK(dfr) | CMASK(dfl) | CMASK(dbl) | CMASK(dbr))
-#define _cmask_r (CMASK(ufr) | CMASK(dfr) | CMASK(ubr) | CMASK(dbr))
-#define _cmask_l (CMASK(ufl) | CMASK(dfl) | CMASK(ubl) | CMASK(dbl))
-#define _cmask_f (CMASK(ufr) | CMASK(ufl) | CMASK(dfr) | CMASK(dfl))
-#define _cmask_b (CMASK(ubr) | CMASK(ubl) | CMASK(dbr) | CMASK(dbl))
-
-#define _eomask (EOMASK(uf) | EOMASK(ul) | EOMASK(ub) | EOMASK(ur) \
- EOMASK(df) | EOMASK(dl) | EOMASK(db) | EOMASK(dr) \
- EOMASK(fr) | EOMASK(fl) | EOMASK(bl) | EOMASK(br))
-#define _comask (COMASK(ufr) | COMASK(ufl) | COMASK(ubl) | COMASK(ubr) \
- COMASK(dfr) | COMASK(dfl) | COMASK(dbl) | COMASK(dbr))
-
-static uint64_t permsign(uint64_t *, int);
-static uint64_t readep(char *);
-static uint64_t readeo(char *);
-static uint64_t readcp(char *);
-static uint64_t readco(char *);
-static uint64_t readmove(char);
-static uint64_t readmodifier(char);
-
-static char *edgestr[] = {
- [_edge_uf] = "UF",
- [_edge_ub] = "UB",
- [_edge_db] = "DB",
- [_edge_df] = "DF",
- [_edge_ur] = "UR",
- [_edge_ul] = "UL",
- [_edge_dl] = "DL",
- [_edge_dr] = "DR",
- [_edge_fr] = "FR",
- [_edge_fl] = "FL",
- [_edge_bl] = "BL",
- [_edge_br] = "BR"
-};
-static char *cornerstr[] = {
- [_corner_ufr] = "UFR",
- [_corner_ubl] = "UBL",
- [_corner_dfl] = "DFL",
- [_corner_dbr] = "DBR",
- [_corner_ufl] = "UFL",
- [_corner_ubr] = "UBR",
- [_corner_dfr] = "DFR",
- [_corner_dbl] = "DBL"
-};
-static char *movestr[] = {
- [U] = "U", [U2] = "U2", [U3] = "U'",
- [D] = "D", [D2] = "D2", [D3] = "D'",
- [R] = "R", [R2] = "R2", [R3] = "R'",
- [L] = "L", [L2] = "L2", [L3] = "L'",
- [F] = "F", [F2] = "F2", [F3] = "F'",
- [B] = "B", [B2] = "B2", [B3] = "B'",
-};
-
-cube_t solvedcube = {
- .e = ESOLVED(uf) | ESOLVED(ul) | ESOLVED(ub) | ESOLVED(ur) |
- ESOLVED(df) | ESOLVED(dl) | ESOLVED(db) | ESOLVED(dr) |
- ESOLVED(fr) | ESOLVED(fl) | ESOLVED(bl) | ESOLVED(br),
- .c = CSOLVED(ufr) | CSOLVED(ufl) | CSOLVED(ubl) | CSOLVED(ubr) |
- CSOLVED(dfr) | CSOLVED(dfl) | CSOLVED(dbl) | CSOLVED(dbr),
-};
-cube_t errorcube = { .e = _error, .c = _error };
-
-
-static uint64_t
-permsign(uint64_t *a, int n)
-{
- int i, j;
- uint64_t ret;
-
- ret = 0;
-
- for (i = 0; i < n; i++)
- for (j = i+1; j < n; j++)
- ret += a[i] > a[j] ? 1 : 0;
-
- return ret % 2;
-}
-
-bool
-isconsistent(cube_t cube)
-{
- uint64_t p[12], sum;
- bool found[12];
- int i;
-
- sum = 0;
-
- /* Check for EP consistency */
- for (i = 0; i < 12; i++)
- found[i] = false;
- for (i = 0; i < 12; i++) {
- p[i] = EPAT(cube.e, i);
- found[p[i]] = true;
- }
- for (i = 0; i < 12; i++)
- if (!found[i])
- return false;
- sum = permsign(p, 12);
-
- /* Check for CP consistency */
- for (i = 0; i < 8; i++)
- found[i] = false;
- for (i = 0; i < 8; i++) {
- p[i] = CPAT(cube.c, i);
- found[p[i]] = true;
- }
- for (i = 0; i < 8; i++)
- if (!found[i])
- return false;
- sum += permsign(p, 8);
-
- /* Check permutation parity */
- if (sum % 2 != 0)
- return false;
-
- /* Check for EO parity */
- for (i = 0, sum = 0; i < 12; i++)
- sum += EOAT(cube.e, i);
- if (sum % 2 != 0)
- return false;
-
- /* Check for CO parity */
- for (i = 0, sum = 0; i < 8; i++)
- sum += COAT(cube.c, i);
- if (sum % 3 != 0)
- return false;
-
- /* Check that CO extra bit is zero */
- for (i = 0; i < 8; i++)
- if (cube.c & (1ULL << (5 + i * _csize)))
- return false;
-
- return true;
-}
-
-bool
-issolved(cube_t cube)
-{
- return cube.c == solvedcube.c && cube.e == solvedcube.e;
-}
-
-
-static uint64_t
-readep(char *str)
-{
- if (!strncmp(str, "UF", 2))
- return _edge_uf;
- if (!strncmp(str, "UL", 2))
- return _edge_ul;
- if (!strncmp(str, "UB", 2))
- return _edge_ub;
- if (!strncmp(str, "UR", 2))
- return _edge_ur;
- if (!strncmp(str, "DF", 2))
- return _edge_df;
- if (!strncmp(str, "DL", 2))
- return _edge_dl;
- if (!strncmp(str, "DB", 2))
- return _edge_db;
- if (!strncmp(str, "DR", 2))
- return _edge_dr;
- if (!strncmp(str, "FR", 2))
- return _edge_fr;
- if (!strncmp(str, "FL", 2))
- return _edge_fl;
- if (!strncmp(str, "BL", 2))
- return _edge_bl;
- if (!strncmp(str, "BR", 2))
- return _edge_br;
-
- return _error;
-}
-
-static uint64_t
-readeo(char *str)
-{
- if (*str == '0')
- return 0ULL;
- if (*str == '1')
- return 1ULL;
-
- return _error;
-}
-
-static uint64_t
-readcp(char *str)
-{
- if (!strncmp(str, "UFR", 3) || !strncmp(str, "URF", 3))
- return _corner_ufr;
- if (!strncmp(str, "UFL", 3) || !strncmp(str, "ULF", 3))
- return _corner_ufl;
- if (!strncmp(str, "UBL", 3) || !strncmp(str, "ULB", 3))
- return _corner_ubl;
- if (!strncmp(str, "UBR", 3) || !strncmp(str, "URB", 3))
- return _corner_ubr;
- if (!strncmp(str, "DFR", 3) || !strncmp(str, "DRF", 3))
- return _corner_dfr;
- if (!strncmp(str, "DFL", 3) || !strncmp(str, "DLF", 3))
- return _corner_dfl;
- if (!strncmp(str, "DBL", 3) || !strncmp(str, "DLB", 3))
- return _corner_dbl;
- if (!strncmp(str, "DBR", 3) || !strncmp(str, "DRB", 3))
- return _corner_dbr;
-
- return _error;
-}
-
-static uint64_t
-readco(char *str)
-{
- if (*str == '0')
- return 0ULL;
- if (*str == '1')
- return 1ULL;
- if (*str == '2')
- return 2ULL;
-
- return _error;
-}
-
-cube_t
-readcube(char *buf)
-{
- int i;
- uint64_t piece, orient;
- cube_t ret = {0};
- char *b = buf;
-
- for (i = 0; i < 12; i++) {
- while (*b == ' ' || *b == '\t' || *b == '\n')
- b++;
- if ((piece = readep(b)) == _error)
- goto readcube_error;
- b += 2;
- if ((orient = readeo(b)) == _error)
- goto readcube_error;
- b++;
- ret.e |= (piece << ESHIFT(i)) | (orient << EOSHIFT(i));
- }
- for (i = 0; i < 8; i++) {
- while (*b == ' ' || *b == '\t' || *b == '\n')
- b++;
- if ((piece = readcp(b)) == _error)
- goto readcube_error;
- b += 3;
- if ((orient = readco(b)) == _error)
- goto readcube_error;
- b++;
- ret.c |= (piece << CSHIFT(i)) | (orient << COSHIFT(i));
- }
-
- return ret;
-
-readcube_error:
- return errorcube;
-}
-
-void
-writecube(cube_t cube, char *buf)
-{
- char *errormsg;
- uint64_t piece;
- size_t len;
- int i;
-
- if (!isconsistent(cube)) {
- errormsg = "ERROR: cannot write inconsistent cube";
- goto writecube_error;
- }
-
- for (i = 0; i < 12; i++) {
- piece = EPAT(cube.e, i);
- buf[4*i ] = edgestr[piece][0];
- buf[4*i + 1] = edgestr[piece][1];
- buf[4*i + 2] = EOAT(cube.e, i) + '0';
- buf[4*i + 3] = ' ';
- }
- for (i = 0; i < 8; i++) {
- piece = CPAT(cube.c, i);
- buf[48 + 5*i ] = cornerstr[piece][0];
- buf[48 + 5*i + 1] = cornerstr[piece][1];
- buf[48 + 5*i + 2] = cornerstr[piece][2];
- buf[48 + 5*i + 3] = COAT(cube.c, i) + '0';
- buf[48 + 5*i + 4] = ' ';
- }
-
- buf[48+39] = '\0';
-
- return;
-
-writecube_error:
- len = strlen(errormsg);
- strcpy(buf, errormsg);
- buf[len] = '\n';
- buf[len+1] = '\0';
-}
-
-
-static uint64_t
-readmove(char c)
-{
- switch (c) {
- case 'U':
- return U;
- case 'D':
- return D;
- case 'R':
- return R;
- case 'L':
- return L;
- case 'F':
- return F;
- case 'B':
- return B;
- default:
- return _error;
- }
-}
-
-static uint64_t
-readmodifier(char c)
-{
- switch (c) {
- case '1': /* Fallthrough */
- case '2': /* Fallthrough */
- case '3':
- return c - '0' - 1;
- case '\'':
- return 2;
- default:
- return 0;
- }
-}
-
-int
-readmoves(char *buf, move_t *m)
-{
- int n;
- uint64_t r;
- char *b;
-
- for (b = buf, n = 0; *b != '\0'; b++) {
- while (*b == ' ' || *b == '\t' || *b == '\n')
- b++;
- if ((r = readmove(*b)) == _error)
- return -1;
- m[n] = (move_t)r;
- if ((r = readmodifier(*(b+1))) != 0) {
- b++;
- m[n] += r;
- }
- n++;
- }
-
- return n;
-}
-
-void
-writemoves(move_t *m, int n, char *buf)
-{
- int i;
- char *b, *s;
-
- for (i = 0, b = buf; i < n; i++, b++) {
- s = movestr[m[i]];
- strcpy(b, s);
- b += strlen(s);
- *b = ' ';
- }
- *b = '\0';
-}
-
-
-cube_t
-move(move_t m, cube_t c)
-{
- /* TODO - not implemented yet */
-
- cube_t ret = {0};
-
- switch (m) {
- case U:
- return ret;
- default:
- return ret;
- }
-}
diff --git a/src/cube.sync-conflict-20230524-182143-JOKKFPA.h b/src/cube.sync-conflict-20230524-182143-JOKKFPA.h
@@ -1,27 +0,0 @@
-typedef enum {
- U, U2, U3, D, D2, D3,
- R, R2, R3, L, L2, L3,
- F, F2, F3, B, B2, B3
-} move_t;
-typedef struct {
- uint64_t e;
- uint64_t c;
-} cube_t;
-
-extern cube_t solvedcube;
-extern cube_t errorcube;
-
-bool isconsistent(cube_t);
-bool issolved(cube_t);
-
-cube_t readcube(char *);
-void writecube(cube_t, char *);
-
-int readmoves(char *, move_t *);
-void writemoves(move_t *, int, char *);
-
-/*
-cube_t move(move_t, cube_t);
-cube_t inverse(cube_t);
-
-*/
diff --git a/src/cube.sync-conflict-20230524-182146-JOKKFPA.c b/src/cube.sync-conflict-20230524-182146-JOKKFPA.c
@@ -1,614 +0,0 @@
-/*
-# Cube representation, moves, transformations and indexing
-
-## String description
-
-The functions readcube() and writecube() use the following format.
-Each edge is represented by two letters denoting the sides it belongs to
-and one number denoting its orientation (0 oriented, 1 mis-oriented).
-Similarly, each corner is represented by three letters and a number
-(0 oriented, 1 twisted clockwise, 2 twisted counter-clockwise).
-Edge orientation is relative to the F / B axis, corner orientation is
-relative to the U / D axis.
-
-The correct order of the pieces is the same as that defined in the
-section "Internal cube representation", except that pieces are read
-left-to-right. Pieces are divided by slices, so the ordering is not the
-most intuitive, but it is more convenient for the internal representation.
-
-Whitespaces between pieces are ignored when reading the cube, and a
-single whitespace character is added between pieces when writing.
-
-For example, the solved cube looks like this:
-
-UF0 UB0 DB0 DF0 UR0 UL0 DL0 DR0 FR0 FL0 BL0 BR0 UFR0 UBL0 DFL0 DBR0 UFL0 UBR0 DFR0 DBL0
-
-The cube after the moves R'U'F looks like this:
-
-FL1 BR0 DB0 UR1 UF0 UB0 DL0 FR0 UL1 DF1 BL0 DR0 UBL1 DBR1 UFR2 DFR2 DFL2 UBL2 UFL2 DBL0
-
-More formats might be supported in the future.
-
-## Internal cube representation
-
-The cube_t data structure implemented in this file is designed to
-efficiently perform common operations on a 3x3x3 Rubik's cube when
-solving it with an iterative-deepening DFS search. It is not the most
-general, complete, easy to read or compact one. Since the cube can
-be trivially reoriented before the search, we only encode permutations
-of the cube that keep the center pieces in a fixed position (that is,
-we do not encode the position of the centers).
-
-The cube state is encoded in two 64-bit integers, one for edges and one
-for centers. We explain how edges are encoded first, and the highlight
-the few differences with corners afterwards.
-
-For encoding edges, only the 60 least-significant bits are used. Each
-edge described by 5 bits. The position of a 5-bit block in the 64-bit
-integer determine the position of the edge piece in the cube, according
-to the following table (least-significant bits on the right):
-
-55-59 50-54 45-49 40-44 35-39 30-34 25-29 20-24 15-19 10-14 5-9 0-4
- BR BL FL FR DR DL UL UR DF DB UB UF
-ossee ossee ossee ossee ossee ossee ossee ossee ossee ossee ossee ossee
-
-For each edge, the 4 least-significant bits ('ssee' in the table)
-determine the piece. The two bits marked with 'ss' determine the internal
-slice the piece belongs to, i.e. they are either '00' for M, '01' for
-S or '10' for E. The other two bits (marked with 'ee') determine the
-actual edge piece among the 4 in the same slice, and they are assigned
-somewhat arbitarily. Using this representation and the ordering defined
-in the table above, the edges are correctly permuted when these 4 bits
-for each represent the numbers 0 to 11 in the correct order.
-
-The last bit determines the orientation. The orientation of an edge
-depends on its position, and it is defined being 0 if the edge can be
-moved to its place in the solved orientation by permutations in the
-subgroup <U, D, R, L, F2, B2>.
-
-Corners are encoded in the 48 least-significant bits, and are described
-by 6 bits each, their position being defined by the following table:
-
- 35-39 30-34 25-29 20-24 15-19 10-14 5-9 0-4
- DBL DFL UBR UFL DBR DFL UBL UFR
-oooxcc oooxcc oooxcc oooxcc oooxcc oooxcc oooxcc oooxcc
-
-The bit marked with an 'x' describes the axis the corner belongs to.
-The 0 axis consists of the corners UFR, UBL, DFL and DBR, and the other
-four corners form the axis marked with 1. Then two bits are needed to
-identify the corner among the four of the same axis. The last three bits
-determine the orientation, where one corner is defined to be oriented
-(marked with '000') if its top or bottom sticker faces the top or bottom
-side. A corner a clockwise turn away from being oriented, thus requiring
-a counter-clockwise turn to be oriented correctly, is marked with '001',
-and a corner a counter-clockwise turn away is marked with '010'. The most
-significant bit is not used to determine the corner orientation, but it
-must always be set to '0' to simplify the moving operations (see below).
-
-## Basic moves
-
-The 18 basic moves of the cube could be performed by applying a suitable
-general permutation (see below), but they have instead been manually
-implemented with a few simple operations each, to improve performance.
-
-For each move we first permute the pieces. This amounts to shifting
-around 4 blocks of bits for edges and 4 for corners. Since in some cases
-adjacent pieces on the cube are also adjacent in the bit representation we
-use, we can save some operations by shifting multiple blocks together.
-For example, for the move U for edges we shift a block of 15 bits 5
-positions to the left and a block of 5 bits 15 positions to the right.
-
-There are some moves that change the orientation of the pieces. Namely,
-the moves F, F', B and B' change the orientation of the edges and those
-moves as well as R, R', L and L' change the orientation of the corners.
-Edge orientation is easy to address: we simply xor the edge representation
-by a bit mask with zeroes everywhere except for the 4 edges that need
-to be flipped (i.e. the ones on the twisted face).
-
-Corner orientation is harder to reproduce efficiently working only with
-bitwise operations, as it involves performing operations modulo 3.
-However, with the help of the extra bit we reserved, we are able to
-do this using only two additions and 3 bitwise operations, without
-any multiplication, division or modulo operation. The trick is
-to use the following formula to sum two numbers x, y in {0,1,2}:
-
- ((x+y) + (x+y+1)/4) % 4
-
-The thrid bit is needed because x+y and x+y+1 can exceed 3.
-See below (in the code) for the details.
-
-## Inverting the cube
-
-TODO
-
-## Transformations (conjugations by full-cube rotations)
-
-TODO
-
-## Indexing
-
-TODO - subgroup description etc
-
-Ideas for pruning (for another file?):
-- Use corner separation + CO as main coordinate (~150k states)
- - for huge tables, htr corners can be used (6 times larger)
-- Symmetry table, one entry or each main coordinate value with the
- following info:
- - index of the corresponding main symcoord (13 bits)
- - transtorep (6 bits)
- - base value for pruning table (5 bits, probably 4)
- - pruning value for only main coord, i.e. fallback (4 bits)
-- To get a full coord for the cube:
- - get first coord c, get the transtorep
- - transform edges with transtorep
- - get second coordinate e
- - return c * MAXE + e
- - This is still too big, so divide by a power of 2 to get the hashed index
- - second coordinate: ep always, + varible number of eo bit (0 to 11)
-- Generate table:
- - first probe for base value:
- - solve coord using fallback table for pruning for 10k random states or so
- - loop over all possible values (even if going for smaller table)
- - with inverse-index strategy or what?
- - use 1 bit per entry (more than base value or not)
-*/
-
-#include <stdbool.h>
-#include <stdint.h>
-#include <string.h>
-
-#ifdef DEBUG
-#include <stdio.h>
-#endif
-
-#include "cube.h"
-
-#define _error 0xFFFFFFFF
-
-#define _esize 5ULL
-#define _eoblock 0x10ULL /* 10000 */
-#define _epblock 0x0FULL /* 01111 */
-#define _eblock 0x1FULL /* 11111 */
-
-#define _csize 6ULL
-#define _coblock 0x18ULL /* 011000 */
-#define _cpblock 0x07ULL /* 000111 */
-#define _cblock 0x3FULL /* 111111 */
-
-#define _edge_uf 0ULL /* 00 00 */
-#define _edge_ub 1ULL /* 00 01 */
-#define _edge_db 2ULL /* 00 10 */
-#define _edge_df 3ULL /* 00 11 */
-#define _edge_ur 4ULL /* 01 00 */
-#define _edge_ul 5ULL /* 01 01 */
-#define _edge_dl 6ULL /* 01 10 */
-#define _edge_dr 7ULL /* 01 11 */
-#define _edge_fr 8ULL /* 10 00 */
-#define _edge_fl 9ULL /* 10 01 */
-#define _edge_bl 10ULL /* 10 10 */
-#define _edge_br 11ULL /* 10 11 */
-
-#define _corner_ufr 0ULL /* 0 00 */
-#define _corner_ubl 1ULL /* 0 01 */
-#define _corner_dfl 2ULL /* 0 10 */
-#define _corner_dbr 3ULL /* 0 11 */
-#define _corner_ufl 4ULL /* 1 00 */
-#define _corner_ubr 5ULL /* 1 01 */
-#define _corner_dfr 6ULL /* 1 10 */
-#define _corner_dbl 7ULL /* 1 11 */
-
-#define ESHIFT(i) ((i) * _esize)
-#define EOSHIFT(i) (4ULL + (i) * _esize)
-#define EMASK(i) (_eblock << ESHIFT(i))
-#define EOMASK(i) (_eoblock << ESHIFT(i))
-#define EPMASK(i) (_epblock << ESHIFT(i))
-#define ESOLVED(ee) (_edge_##ee << (_edge_##ee * _esize))
-#define EDGEAT(e, i) (((e) & EMASK(i)) >> ESHIFT(i))
-#define EOAT(e, i) (((e) & EOMASK(i)) >> EOSHIFT(i))
-#define EPAT(e, i) (((e) & EPMASK(i)) >> ESHIFT(i))
-
-#define CSHIFT(i) ((i) * _csize)
-#define COSHIFT(i) (3ULL + (i) * _csize)
-#define CMASK(i) (_cblock << CSHIFT(i))
-#define COMASK(i) (_coblock << CSHIFT(i))
-#define CPMASK(i) (_cpblock << CSHIFT(i))
-#define CSOLVED(ccc) (_corner_##ccc << (_corner_##ccc * _csize))
-#define CORNERAT(c, i) (((c) & CMASK(i)) >> CSHIFT(i))
-#define COAT(c, i) (((c) & COMASK(i)) >> COSHIFT(i))
-#define CPAT(c, i) (((c) & CPMASK(i)) >> CSHIFT(i))
-
-#define _emask_u (EMASK(uf) | EMASK(ul) | EMASK(ub) | EMASK(ur))
-#define _emask_d (EMASK(df) | EMASK(dl) | EMASK(db) | EMASK(dr))
-#define _emask_r (EMASK(ur) | EMASK(dr) | EMASK(fr) | EMASK(br))
-#define _emask_l (EMASK(ul) | EMASK(dl) | EMASK(fl) | EMASK(bl))
-#define _emask_f (EMASK(uf) | EMASK(df) | EMASK(fr) | EMASK(fl))
-#define _emask_b (EMASK(ub) | EMASK(db) | EMASK(br) | EMASK(bl))
-
-#define _cmask_u (CMASK(ufr) | CMASK(ufl) | CMASK(ubl) | CMASK(ubr))
-#define _cmask_d (CMASK(dfr) | CMASK(dfl) | CMASK(dbl) | CMASK(dbr))
-#define _cmask_r (CMASK(ufr) | CMASK(dfr) | CMASK(ubr) | CMASK(dbr))
-#define _cmask_l (CMASK(ufl) | CMASK(dfl) | CMASK(ubl) | CMASK(dbl))
-#define _cmask_f (CMASK(ufr) | CMASK(ufl) | CMASK(dfr) | CMASK(dfl))
-#define _cmask_b (CMASK(ubr) | CMASK(ubl) | CMASK(dbr) | CMASK(dbl))
-
-#define _eomask (EOMASK(uf) | EOMASK(ul) | EOMASK(ub) | EOMASK(ur) \
- EOMASK(df) | EOMASK(dl) | EOMASK(db) | EOMASK(dr) \
- EOMASK(fr) | EOMASK(fl) | EOMASK(bl) | EOMASK(br))
-#define _comask (COMASK(ufr) | COMASK(ufl) | COMASK(ubl) | COMASK(ubr) \
- COMASK(dfr) | COMASK(dfl) | COMASK(dbl) | COMASK(dbr))
-
-static uint64_t permsign(uint64_t *, int);
-static uint64_t readep(char *);
-static uint64_t readeo(char *);
-static uint64_t readcp(char *);
-static uint64_t readco(char *);
-static uint64_t readmove(char);
-static uint64_t readmodifier(char);
-
-static char *edgestr[] = {
- [_edge_uf] = "UF",
- [_edge_ub] = "UB",
- [_edge_db] = "DB",
- [_edge_df] = "DF",
- [_edge_ur] = "UR",
- [_edge_ul] = "UL",
- [_edge_dl] = "DL",
- [_edge_dr] = "DR",
- [_edge_fr] = "FR",
- [_edge_fl] = "FL",
- [_edge_bl] = "BL",
- [_edge_br] = "BR"
-};
-static char *cornerstr[] = {
- [_corner_ufr] = "UFR",
- [_corner_ubl] = "UBL",
- [_corner_dfl] = "DFL",
- [_corner_dbr] = "DBR",
- [_corner_ufl] = "UFL",
- [_corner_ubr] = "UBR",
- [_corner_dfr] = "DFR",
- [_corner_dbl] = "DBL"
-};
-static char *movestr[] = {
- [U] = "U", [U2] = "U2", [U3] = "U'",
- [D] = "D", [D2] = "D2", [D3] = "D'",
- [R] = "R", [R2] = "R2", [R3] = "R'",
- [L] = "L", [L2] = "L2", [L3] = "L'",
- [F] = "F", [F2] = "F2", [F3] = "F'",
- [B] = "B", [B2] = "B2", [B3] = "B'",
-};
-
-cube_t solvedcube = {
- .e = ESOLVED(uf) | ESOLVED(ul) | ESOLVED(ub) | ESOLVED(ur) |
- ESOLVED(df) | ESOLVED(dl) | ESOLVED(db) | ESOLVED(dr) |
- ESOLVED(fr) | ESOLVED(fl) | ESOLVED(bl) | ESOLVED(br),
- .c = CSOLVED(ufr) | CSOLVED(ufl) | CSOLVED(ubl) | CSOLVED(ubr) |
- CSOLVED(dfr) | CSOLVED(dfl) | CSOLVED(dbl) | CSOLVED(dbr),
-};
-cube_t errorcube = { .e = _error, .c = _error };
-
-
-static uint64_t
-permsign(uint64_t *a, int n)
-{
- int i, j;
- uint64_t ret;
-
- ret = 0;
-
- for (i = 0; i < n; i++)
- for (j = i+1; j < n; j++)
- ret += a[i] > a[j] ? 1 : 0;
-
- return ret % 2;
-}
-
-bool
-isconsistent(cube_t cube)
-{
- uint64_t p[12], sum;
- bool found[12];
- int i;
-
- sum = 0;
-
- /* Check for EP consistency */
- for (i = 0; i < 12; i++)
- found[i] = false;
- for (i = 0; i < 12; i++) {
- p[i] = EPAT(cube.e, i);
- found[p[i]] = true;
- }
- for (i = 0; i < 12; i++)
- if (!found[i])
- return false;
- sum = permsign(p, 12);
-
- /* Check for CP consistency */
- for (i = 0; i < 8; i++)
- found[i] = false;
- for (i = 0; i < 8; i++) {
- p[i] = CPAT(cube.c, i);
- found[p[i]] = true;
- }
- for (i = 0; i < 8; i++)
- if (!found[i])
- return false;
- sum += permsign(p, 8);
-
- /* Check permutation parity */
- if (sum % 2 != 0)
- return false;
-
- /* Check for EO parity */
- for (i = 0, sum = 0; i < 12; i++)
- sum += EOAT(cube.e, i);
- if (sum % 2 != 0)
- return false;
-
- /* Check for CO parity */
- for (i = 0, sum = 0; i < 8; i++)
- sum += COAT(cube.c, i);
- if (sum % 3 != 0)
- return false;
-
- /* Check that CO extra bit is zero */
- for (i = 0; i < 8; i++)
- if (cube.c & (1ULL << (5 + i * _csize)))
- return false;
-
- return true;
-}
-
-bool
-issolved(cube_t cube)
-{
- return cube.c == solvedcube.c && cube.e == solvedcube.e;
-}
-
-
-static uint64_t
-readep(char *str)
-{
- if (!strncmp(str, "UF", 2))
- return _edge_uf;
- if (!strncmp(str, "UL", 2))
- return _edge_ul;
- if (!strncmp(str, "UB", 2))
- return _edge_ub;
- if (!strncmp(str, "UR", 2))
- return _edge_ur;
- if (!strncmp(str, "DF", 2))
- return _edge_df;
- if (!strncmp(str, "DL", 2))
- return _edge_dl;
- if (!strncmp(str, "DB", 2))
- return _edge_db;
- if (!strncmp(str, "DR", 2))
- return _edge_dr;
- if (!strncmp(str, "FR", 2))
- return _edge_fr;
- if (!strncmp(str, "FL", 2))
- return _edge_fl;
- if (!strncmp(str, "BL", 2))
- return _edge_bl;
- if (!strncmp(str, "BR", 2))
- return _edge_br;
-
- return _error;
-}
-
-static uint64_t
-readeo(char *str)
-{
- if (*str == '0')
- return 0ULL;
- if (*str == '1')
- return 1ULL;
-
- return _error;
-}
-
-static uint64_t
-readcp(char *str)
-{
- if (!strncmp(str, "UFR", 3) || !strncmp(str, "URF", 3))
- return _corner_ufr;
- if (!strncmp(str, "UFL", 3) || !strncmp(str, "ULF", 3))
- return _corner_ufl;
- if (!strncmp(str, "UBL", 3) || !strncmp(str, "ULB", 3))
- return _corner_ubl;
- if (!strncmp(str, "UBR", 3) || !strncmp(str, "URB", 3))
- return _corner_ubr;
- if (!strncmp(str, "DFR", 3) || !strncmp(str, "DRF", 3))
- return _corner_dfr;
- if (!strncmp(str, "DFL", 3) || !strncmp(str, "DLF", 3))
- return _corner_dfl;
- if (!strncmp(str, "DBL", 3) || !strncmp(str, "DLB", 3))
- return _corner_dbl;
- if (!strncmp(str, "DBR", 3) || !strncmp(str, "DRB", 3))
- return _corner_dbr;
-
- return _error;
-}
-
-static uint64_t
-readco(char *str)
-{
- if (*str == '0')
- return 0ULL;
- if (*str == '1')
- return 1ULL;
- if (*str == '2')
- return 2ULL;
-
- return _error;
-}
-
-cube_t
-readcube(char *buf)
-{
- int i;
- uint64_t piece, orient;
- cube_t ret = {0};
- char *b = buf;
-
- for (i = 0; i < 12; i++) {
- while (*b == ' ' || *b == '\t' || *b == '\n')
- b++;
- if ((piece = readep(b)) == _error)
- goto readcube_error;
- b += 2;
- if ((orient = readeo(b)) == _error)
- goto readcube_error;
- b++;
- ret.e |= (piece << ESHIFT(i)) | (orient << EOSHIFT(i));
- }
- for (i = 0; i < 8; i++) {
- while (*b == ' ' || *b == '\t' || *b == '\n')
- b++;
- if ((piece = readcp(b)) == _error)
- goto readcube_error;
- b += 3;
- if ((orient = readco(b)) == _error)
- goto readcube_error;
- b++;
- ret.c |= (piece << CSHIFT(i)) | (orient << COSHIFT(i));
- }
-
- return ret;
-
-readcube_error:
- return errorcube;
-}
-
-void
-writecube(cube_t cube, char *buf)
-{
- char *errormsg;
- uint64_t piece;
- size_t len;
- int i;
-
- if (!isconsistent(cube)) {
- errormsg = "ERROR: cannot write inconsistent cube";
- goto writecube_error;
- }
-
- for (i = 0; i < 12; i++) {
- piece = EPAT(cube.e, i);
- buf[4*i ] = edgestr[piece][0];
- buf[4*i + 1] = edgestr[piece][1];
- buf[4*i + 2] = EOAT(cube.e, i) + '0';
- buf[4*i + 3] = ' ';
- }
- for (i = 0; i < 8; i++) {
- piece = CPAT(cube.c, i);
- buf[48 + 5*i ] = cornerstr[piece][0];
- buf[48 + 5*i + 1] = cornerstr[piece][1];
- buf[48 + 5*i + 2] = cornerstr[piece][2];
- buf[48 + 5*i + 3] = COAT(cube.c, i) + '0';
- buf[48 + 5*i + 4] = ' ';
- }
-
- buf[48+39] = '\0';
-
- return;
-
-writecube_error:
- len = strlen(errormsg);
- strcpy(buf, errormsg);
- buf[len] = '\n';
- buf[len+1] = '\0';
-}
-
-
-static uint64_t
-readmove(char c)
-{
- switch (c) {
- case 'U':
- return U;
- case 'D':
- return D;
- case 'R':
- return R;
- case 'L':
- return L;
- case 'F':
- return F;
- case 'B':
- return B;
- default:
- return _error;
- }
-}
-
-static uint64_t
-readmodifier(char c)
-{
- switch (c) {
- case '1': /* Fallthrough */
- case '2': /* Fallthrough */
- case '3':
- return c - '0' - 1;
- case '\'':
- return 2;
- default:
- return 0;
- }
-}
-
-int
-readmoves(char *buf, move_t *m)
-{
- int n;
- uint64_t r;
- char *b;
-
- for (b = buf, n = 0; *b != '\0'; b++) {
- while (*b == ' ' || *b == '\t' || *b == '\n')
- b++;
- if ((r = readmove(*b)) == _error)
- return -1;
- m[n] = (move_t)r;
- if ((r = readmodifier(*(b+1))) != 0) {
- b++;
- m[n] += r;
- }
- n++;
- }
-
- return n;
-}
-
-void
-writemoves(move_t *m, int n, char *buf)
-{
- int i;
- char *b, *s;
-
- for (i = 0, b = buf; i < n; i++, b++) {
- s = movestr[m[i]];
- strcpy(b, s);
- b += strlen(s);
- *b = ' ';
- }
- *b = '\0';
-}
-
-
-cube_t
-move(move_t m, cube_t c)
-{
- /* TODO - not implemented yet */
-
- cube_t ret = {0};
-
- switch (m) {
- case U:
- return ret;
- default:
- return ret;
- }
-}
diff --git a/src/cube.sync-conflict-20230524-182146-JOKKFPA.h b/src/cube.sync-conflict-20230524-182146-JOKKFPA.h
@@ -1,27 +0,0 @@
-typedef enum {
- U, U2, U3, D, D2, D3,
- R, R2, R3, L, L2, L3,
- F, F2, F3, B, B2, B3
-} move_t;
-typedef struct {
- uint64_t e;
- uint64_t c;
-} cube_t;
-
-extern cube_t solvedcube;
-extern cube_t errorcube;
-
-bool isconsistent(cube_t);
-bool issolved(cube_t);
-
-cube_t readcube(char *);
-void writecube(cube_t, char *);
-
-int readmoves(char *, move_t *);
-void writemoves(move_t *, int, char *);
-
-/*
-cube_t move(move_t, cube_t);
-cube_t inverse(cube_t);
-
-*/
