From 4d08bf731a099de2d174c73489636e1a12935aee Mon Sep 17 00:00:00 2001 From: Sebastiano Tronto Date: Fri, 8 Sep 2023 18:28:30 +0200 Subject: New implementation, moved old to experiments/ --- experiments/cube.c | 888 +++++++++++++++++++++++++++++++++++++++++++++++++++++ experiments/cube.h | 27 ++ 2 files changed, 915 insertions(+) create mode 100644 experiments/cube.c create mode 100644 experiments/cube.h (limited to 'experiments') diff --git a/experiments/cube.c b/experiments/cube.c new file mode 100644 index 0000000..4372b5e --- /dev/null +++ b/experiments/cube.c @@ -0,0 +1,888 @@ +/* +# Cube representation, moves, transformations and (tentatively) indexing + +## Textual 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 \ (no newline) +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 \ (no newline) +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 . + +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. + +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. We can +apply this operation to multiple pairs of bits representing ternary +digits at once using binary operations. See the function coapply() +below for the details. + +## Inverting the cube + +TODO + +## Transformations (conjugations by full-cube rotations) + +TODO + +## Indexing (tentative) + +TODO - subgroup description etc + +*/ + +#include +#include +#include + +#ifdef DEBUG +#include +#endif + +#include "cube.h" + +#define _error 0xFFFFFFFF + +#define _eoblock 0x10ULL /* 10000 */ +#define _epblock 0x0FULL /* 01111 */ +#define _eblock 0x1FULL /* 11111 */ +#define _eblock2 0x3FFULL /* 1111111111 */ + +#define _coblock 0x18ULL /* 011000 */ +#define _cpblock 0x07ULL /* 000111 */ +#define _cblock 0x3FULL /* 111111 */ +#define _cblock2 0xFFFULL /* 111111111111 */ + +#define _eomask 0x842108421084210ULL /* 10000 repeated 12 times */ +#define _comask 0x618618618618ULL /* 011000 repeated 8 times */ +#define _coonemask 0x208208208208ULL /* 001000 repeated 8 times */ +#define _coextramask 0x820820820820ULL /* 100000 repeated 8 times */ + +#define _emask_u (_eblock2 | _eblock2 << 20ULL) +#define _emask_d (_eblock2 << 10ULL | _eblock2 << 30ULL) +#define _emask_r (_eblock << 20ULL | _eblock2 << 35ULL | _eblock << 55ULL) +#define _emask_l (_eblock2 << 45ULL | _eblock2 << 25ULL) +#define _emask_f (_eblock | _eblock << 15ULL | _eblock2 << 40ULL) +#define _emask_b (_eblock2 << 5ULL | _eblock2 << 50ULL) + +#define _cmask_u (_cblock2 | _cblock2 << 24ULL) +#define _cmask_d (_cblock2 << 12ULL | _cblock2 << 36ULL) +#define _cmask_r (_cblock | _cblock << 18ULL | _cblock2 << 30ULL) +#define _cmask_l (_cblock2 << 6ULL | _cblock << 24ULL | _cblock << 42ULL) +#define _cmask_f (_cblock | _cblock << 12ULL | _cblock << 24ULL | _cblock << 36ULL) +#define _cmask_b (_cblock << 6ULL | _cblock << 18ULL | _cblock << 30ULL | _cblock << 42ULL) + +#define _eomask_f (1ULL << 4ULL | 1ULL << 19ULL | 1ULL << 44ULL | 1ULL << 49ULL) +#define _eomask_b (1ULL << 9ULL | 1ULL << 14ULL | 1ULL << 54ULL | 1ULL << 59ULL) + +#define _comask_r (2ULL << 3ULL | 1ULL << 33ULL | 2ULL << 21ULL | 1ULL << 39ULL) +#define _comask_l (1ULL << 27ULL | 2ULL << 9ULL | 2ULL << 15ULL | 1ULL << 45ULL) +#define _comask_f (1ULL << 3ULL | 1ULL << 15ULL | 2ULL << 27ULL | 2ULL << 39ULL) +#define _comask_b (1ULL << 9ULL | 1ULL << 21ULL | 2ULL << 33ULL | 2ULL << 45ULL) + +static inline uint64_t coapply(uint64_t, uint64_t); +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[] = { + "UF", "UB", "DB", "DF", + "UR", "UL", "DL", "DR", + "FR", "FL", "BL", "BR" +}; +static char *cornerstr[] = { + "UFR", "UBL", "DFL", "DBR", + "UFL", "UBR", "DFR", "DBL" +}; +static char *cornerstralt[] = { + "URF", "ULB", "DLF", "DRB", + "ULF", "URB", "DRF", "DLB" +}; +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 = 0x5A928398A418820ULL, .c = 0x1C61440C2040ULL }; +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 x, p[12], sum, co; + bool found[12]; + int i; + + sum = 0; + + /* Check for EP consistency */ + for (i = 0; i < 12; i++) + found[i] = false; + for (i = 0, x = cube.e; i < 12; i++, x >>= 5ULL) { + p[i] = x & _epblock; + if (p[i] >= 12) + goto inconsistent_ep; + found[p[i]] = true; + } + for (i = 0; i < 12; i++) + if (!found[i]) + goto inconsistent_ep; + sum = permsign(p, 12); + + /* Check for CP consistency */ + for (i = 0; i < 8; i++) + found[i] = false; + for (i = 0, x = cube.c; i < 8; i++, x >>= 6ULL) { + p[i] = x & _cpblock; + if (p[i] >= 8) + goto inconsistent_cp; + found[p[i]] = true; + } + for (i = 0; i < 8; i++) + if (!found[i]) + goto inconsistent_cp; + sum += permsign(p, 8); + + /* Check permutation parity */ + if (sum % 2 != 0) + goto inconsistent_parity; + + /* Check for EO parity */ + for (i = 0, sum = 0, x = cube.e; i < 12; i++, x >>= 5ULL) + sum += (x & _eoblock) >> 4ULL; + if (sum % 2 != 0) + goto inconsistent_eo; + + /* Check for CO parity */ + for (i = 0, sum = 0, x = cube.c; i < 8; i++, x >>= 6ULL) { + co = (x & _coblock) >> 3ULL; + if (co > 2) + goto inconsistent_co3; + sum += co; + } + if (sum % 3 != 0) + goto inconsistent_co; + + /* Check that CO extra bit is zero */ + if (cube.c & _coextramask) + goto inconsistent_coextra; + + return true; + +inconsistent_ep: +#ifdef DEBUG + fprintf(stderr, "Inconsistent EP\n"); +#endif + goto inconsistent_return; +inconsistent_cp: +#ifdef DEBUG + fprintf(stderr, "Inconsistent CP\n"); +#endif + goto inconsistent_return; +inconsistent_parity: +#ifdef DEBUG + fprintf(stderr, "Inconsistent parity\n"); +#endif + goto inconsistent_return; +inconsistent_eo: +#ifdef DEBUG + fprintf(stderr, "Inconsistent EO\n"); +#endif + goto inconsistent_return; +inconsistent_co3: +#ifdef DEBUG + fprintf(stderr, "Inconsistent CO=3\n"); +#endif + goto inconsistent_return; +inconsistent_co: +#ifdef DEBUG + fprintf(stderr, "Inconsistent CO\n"); +#endif + goto inconsistent_return; +inconsistent_coextra: +#ifdef DEBUG + fprintf(stderr, "Inconsistent extra bit for CO\n"); +#endif + goto inconsistent_return; +inconsistent_return: + return false; +} + +bool +issolved(cube_t cube) +{ + return cube.c == solvedcube.c && cube.e == solvedcube.e; +} + + +static uint64_t +readep(char *str) +{ + uint64_t e; + + for (e = 0; e < 12; e++) + if (!strncmp(str, edgestr[e], 2)) + return e; + +#ifdef DEBUG + fprintf(stderr, "Error reading EP\n"); +#endif + return _error; +} + +static uint64_t +readeo(char *str) +{ + if (*str == '0') + return 0ULL; + if (*str == '1') + return 1ULL; + +#ifdef DEBUG + fprintf(stderr, "Error reading EO\n"); +#endif + return _error; +} + +static uint64_t +readcp(char *str) +{ + uint64_t c; + + for (c = 0; c < 8; c++) + if (!strncmp(str, cornerstr[c], 3) || + !strncmp(str, cornerstralt[c], 3)) + return c; + +#ifdef DEBUG + fprintf(stderr, "Error reading CP\n"); +#endif + return _error; +} + +static uint64_t +readco(char *str) +{ + if (*str == '0') + return 0ULL; + if (*str == '1') + return 1ULL; + if (*str == '2') + return 2ULL; + +#ifdef DEBUG + fprintf(stderr, "Error reading CO\n"); +#endif + 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 << (i * 5ULL)) | (orient << (i * 5ULL + 4ULL)); + } + 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 << (i * 6ULL)) | (orient << (i * 6ULL + 3ULL)); + } + + return ret; + +readcube_error: +#ifdef DEBUG + fprintf(stderr, "readcube error\n"); +#endif + return errorcube; +} + +void +writecube(cube_t cube, char *buf) +{ + char *errormsg; + uint64_t piece, orien, x; + size_t len; + int i; + + if (!isconsistent(cube)) { + errormsg = "ERROR: cannot write inconsistent cube"; + goto writecube_error; + } + + for (i = 0, x = cube.e; i < 12; i++, x >>= 5ULL) { + piece = x & _epblock; + orien = (x & _eoblock) >> 4ULL; + buf[4*i ] = edgestr[piece][0]; + buf[4*i + 1] = edgestr[piece][1]; + buf[4*i + 2] = orien + '0'; + buf[4*i + 3] = ' '; + } + for (i = 0, x = cube.c; i < 8; i++, x >>= 6ULL) { + piece = x & _cpblock; + orien = (x & _coblock) >> 3ULL; + 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] = orien + '0'; + buf[48 + 5*i + 4] = ' '; + } + + buf[48+39] = '\0'; + + return; + +writecube_error: +#ifdef DEBUG + fprintf(stderr, "writecube error, see stdout for details\n"); +#endif + len = strlen(errormsg); + memcpy(buf, errormsg, len); + 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 (*b == '\0') + return n; + if ((r = readmove(*b)) == _error) + goto readmoves_error; + m[n] = (move_t)r; + if ((r = readmodifier(*(b+1))) != 0) { + b++; + m[n] += r; + } + n++; + } + + return n; + +readmoves_error: +#ifdef DEBUG + fprintf(stderr, "readmoves error\n"); +#endif + return -1; +} + +void +writemoves(move_t *m, int n, char *buf) +{ + int i; + size_t len; + char *b, *s; + + for (i = 0, b = buf; i < n; i++, b++) { + s = movestr[m[i]]; + len = strlen(s); + memcpy(b, s, len); + b += len; + *b = ' '; + } + *b = '\0'; +} + + +static inline uint64_t +coapply(uint64_t c, uint64_t m) +{ + uint64_t z, b; + + z = c + m; + b = ((z + _coonemask) & _coextramask) >> 2ULL; + + return (z + b) & ~_coextramask; +} + +cube_t +move(cube_t c, move_t m) +{ + cube_t ret = {0}; + +#ifdef DEBUG + if (!isconsistent(c)) { + fprintf(stderr, "move error, inconsistent cube\n"); + goto move_error; + } +#endif + + switch (m) { + case U: + ret.e = c.e & ~_emask_u; + ret.e |= + (c.e & _eblock) << 25ULL | + (c.e & _eblock << 5ULL) << 15ULL | + (c.e & _eblock2 << 20ULL) >> 20ULL; + + ret.c = c.c & ~_cmask_u; + ret.c |= + (c.c & _cblock2) << 24ULL | + (c.c & _cblock << 24ULL) >> 18ULL | + (c.c & _cblock << 30ULL) >> 30ULL; + + return ret; + case U2: + ret.e = c.e & ~_emask_u; + ret.e |= + (c.e & (_eblock | _eblock << 20ULL)) << 5ULL | + (c.e & (_eblock << 5ULL | _eblock << 25ULL)) >> 5ULL; + + ret.c = c.c & ~_cmask_u; + ret.c |= + (c.c & (_cblock | _cblock << 24ULL)) << 6ULL | + (c.c & (_cblock << 6ULL | _cblock << 30ULL)) >> 6ULL; + + return ret; + case U3: + ret.e = c.e & ~_emask_u; + ret.e |= + (c.e & _eblock2) << 20ULL | + (c.e & _eblock << 25ULL) >> 25ULL | + (c.e & _eblock << 20ULL) >> 15ULL; + + ret.c = c.c & ~_cmask_u; + ret.c |= + (c.c & _cblock) << 30ULL | + (c.c & _cblock << 6ULL) << 18ULL | + (c.c & _cblock2 << 24ULL) >> 24ULL; + + return ret; + case D: + ret.e = c.e & ~_emask_d; + ret.e |= + (c.e & _eblock2 << 10ULL) << 20ULL | + (c.e & _eblock << 30ULL) >> 15ULL | + (c.e & _eblock << 35ULL) >> 25ULL; + + ret.c = c.c & ~_cmask_d; + ret.c |= + (c.c & _cblock2 << 12ULL) << 24ULL | + (c.c & _cblock << 36ULL) >> 18ULL | + (c.c & _cblock << 42ULL) >> 30ULL; + + return ret; + case D2: + ret.e = c.e & ~_emask_d; + ret.e |= + (c.e & (_eblock << 10ULL | _eblock << 30ULL)) << 5ULL | + (c.e & (_eblock << 15ULL | _eblock << 35ULL)) >> 5ULL; + + ret.c = c.c & ~_cmask_d; + ret.c |= + (c.c & (_cblock << 12ULL | _cblock << 36ULL)) << 6ULL | + (c.c & (_cblock << 18ULL | _cblock << 42ULL)) >> 6ULL; + + return ret; + case D3: + ret.e = c.e & ~_emask_d; + ret.e |= + (c.e & _eblock << 10ULL) << 25ULL | + (c.e & _eblock << 15ULL) << 15ULL | + (c.e & _eblock2 << 30ULL) >> 20ULL; + + ret.c = c.c & ~_cmask_d; + ret.c |= + (c.c & _cblock << 12ULL) << 30ULL | + (c.c & _cblock << 18ULL) << 18ULL | + (c.c & _cblock2 << 36ULL) >> 24ULL; + + return ret; + case R: + ret.e = c.e & ~_emask_r; + ret.e |= + (c.e & _eblock << 20ULL) << 35ULL | + (c.e & _eblock << 55ULL) >> 20ULL | + (c.e & _eblock << 35ULL) << 5ULL | + (c.e & _eblock << 40ULL) >> 20ULL; + + ret.c = c.c & ~_cmask_r; + ret.c |= + (c.c & _cblock) << 30ULL | + (c.c & _cblock << 30ULL) >> 12ULL | + (c.c & _cblock << 18ULL) << 18ULL | + (c.c & _cblock << 36ULL) >> 36ULL; + + ret.c = coapply(ret.c, _comask_r); + + return ret; + case R2: + ret.e = c.e & ~_emask_r; + ret.e |= + (c.e & (_eblock << 20ULL | _eblock << 40ULL)) << 15ULL | + (c.e & (_eblock << 35ULL | _eblock << 55ULL)) >> 15ULL; + + ret.c = c.c & ~_cmask_r; + ret.c |= + (c.c & _cblock) << 18ULL | + (c.c & _cblock << 18ULL) >> 18ULL | + (c.c & _cblock << 30ULL) << 6ULL | + (c.c & _cblock << 36ULL) >> 6ULL; + + return ret; + case R3: + ret.e = c.e & ~_emask_r; + ret.e |= + (c.e & (_eblock << 20ULL | _eblock << 35ULL)) << 20ULL | + (c.e & _eblock << 55ULL) >> 35ULL | + (c.e & _eblock << 40ULL) >> 5ULL; + + ret.c = c.c & ~_cmask_r; + ret.c |= + (c.c & _cblock) << 36ULL | + (c.c & _cblock << 30ULL) >> 30ULL | + (c.c & _cblock << 18ULL) << 12ULL | + (c.c & _cblock << 36ULL) >> 18ULL; + + ret.c = coapply(ret.c, _comask_r); + + return ret; + case L: + ret.e = c.e & ~_emask_l; + ret.e |= + (c.e & _eblock2 << 25ULL) << 20ULL | + (c.e & _eblock << 45ULL) >> 15ULL | + (c.e & _eblock << 50ULL) >> 25ULL; + + ret.c = c.c & ~_cmask_l; + ret.c |= + (c.c & _cblock << 6ULL) << 18ULL | + (c.c & _cblock << 12ULL) << 30ULL | + (c.c & _cblock << 24ULL) >> 12ULL | + (c.c & _cblock << 42ULL) >> 36ULL; + + ret.c = coapply(ret.c, _comask_l); + + return ret; + case L2: + ret.e = c.e & ~_emask_l; + ret.e |= + (c.e & (_eblock << 25ULL | _eblock << 45ULL)) << 5ULL | + (c.e & (_eblock << 30ULL | _eblock << 50ULL)) >> 5ULL; + + ret.c = c.c & ~_cmask_l; + ret.c |= + (c.c & _cblock << 6ULL) << 6ULL | + (c.c & _cblock << 12ULL) >> 6ULL | + (c.c & _cblock << 24ULL) << 18ULL | + (c.c & _cblock << 42ULL) >> 18ULL; + + return ret; + case L3: + ret.e = c.e & ~_emask_l; + ret.e |= + (c.e & _eblock << 25ULL) << 25ULL | + (c.e & _eblock << 30ULL) << 15ULL | + (c.e & _eblock2 << 45ULL) >> 20ULL; + + ret.c = c.c & ~_cmask_l; + ret.c |= + (c.c & _cblock << 6ULL) << 36ULL | + (c.c & _cblock << 12ULL) << 12ULL | + (c.c & _cblock << 24ULL) >> 18ULL | + (c.c & _cblock << 42ULL) >> 30ULL; + + ret.c = coapply(ret.c, _comask_l); + + return ret; + case F: + ret.e = c.e & ~_emask_f; + ret.e |= + (c.e & _eblock) << 40ULL | + (c.e & _eblock << 15ULL) << 30ULL | + (c.e & _eblock << 40ULL) >> 25ULL | + (c.e & _eblock << 45ULL) >> 45ULL; + + ret.e ^= _eomask_f; + + ret.c = c.c & ~_cmask_f; + ret.c |= + (c.c & _cblock) << 36ULL | + (c.c & (_cblock << 24ULL | _cblock << 36ULL)) >> 24ULL | + (c.c & _cblock << 12ULL) << 12ULL; + + ret.c = coapply(ret.c, _comask_f); + + return ret; + case F2: + ret.e = c.e & ~_emask_f; + ret.e |= + (c.e & _eblock) << 15ULL | + (c.e & _eblock << 15ULL) >> 15ULL | + (c.e & _eblock << 40ULL) << 5ULL | + (c.e & _eblock << 45ULL) >> 5ULL; + + ret.c = c.c & ~_cmask_f; + ret.c |= + (c.c & (_cblock | _cblock << 24ULL)) << 12ULL | + (c.c & (_cblock << 12ULL | _cblock << 36ULL)) >> 12ULL; + + return ret; + case F3: + ret.e = c.e & ~_emask_f; + ret.e |= + (c.e & _eblock) << 45ULL | + (c.e & _eblock << 15ULL) << 25ULL | + (c.e & _eblock << 40ULL) >> 40ULL | + (c.e & _eblock << 45ULL) >> 30ULL; + + ret.e ^= _eomask_f; + + ret.c = c.c & ~_cmask_f; + ret.c |= + (c.c & (_cblock | _cblock << 12ULL)) << 24ULL | + (c.c & _cblock << 24ULL) >> 12ULL | + (c.c & _cblock << 36ULL) >> 36ULL; + + ret.c = coapply(ret.c, _comask_f); + + return ret; + case B: + ret.e = c.e & ~_emask_b; + ret.e |= + (c.e & _eblock2 << 5ULL) << 45ULL | + (c.e & _eblock << 50ULL) >> 40ULL | + (c.e & _eblock << 55ULL) >> 50ULL; + + ret.e ^= _eomask_b; + + ret.c = c.c & ~_cmask_b; + ret.c |= + (c.c & _cblock << 6ULL) << 36ULL | + (c.c & _cblock << 18ULL) << 12ULL | + (c.c & (_cblock << 30ULL | _cblock << 42ULL)) >> 24ULL; + + ret.c = coapply(ret.c, _comask_b); + + return ret; + case B2: + ret.e = c.e & ~_emask_b; + ret.e |= + (c.e & (_eblock << 5ULL | _eblock << 50ULL)) << 5ULL | + (c.e & (_eblock << 10ULL | _eblock << 55ULL)) >> 5ULL; + + ret.c = c.c & ~_cmask_b; + ret.c |= + (c.c & (_cblock << 6ULL | _cblock << 30ULL)) << 12ULL | + (c.c & (_cblock << 18ULL | _cblock << 42ULL)) >> 12ULL; + + return ret; + case B3: + ret.e = c.e & ~_emask_b; + ret.e |= + (c.e & _eblock << 5ULL) << 50ULL | + (c.e & _eblock << 10ULL) << 40ULL | + (c.e & _eblock2 << 50ULL) >> 45ULL; + + ret.e ^= _eomask_b; + + ret.c = c.c & ~_cmask_b; + ret.c |= + (c.c & (_cblock << 6ULL | _cblock << 18ULL)) << 24ULL | + (c.c & _cblock << 30ULL) >> 12ULL | + (c.c & _cblock << 42ULL) >> 36ULL; + + ret.c = coapply(ret.c, _comask_b); + + return ret; + default: + goto move_unknown; + } + +move_unknown: +#ifdef DEBUG + fprintf(stderr, "move error, unknow move\n"); +#endif + goto move_error; +move_error: + return errorcube; +} diff --git a/experiments/cube.h b/experiments/cube.h new file mode 100644 index 0000000..b916f96 --- /dev/null +++ b/experiments/cube.h @@ -0,0 +1,27 @@ +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(cube_t, move_t); + +/* +cube_t inverse(cube_t); +*/ -- cgit v1.3