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STATIC cube_t solvecube(void);
STATIC_INLINE cube_t cubefromarray_ce(uint8_t [static 8], uint8_t [static 12]);
STATIC_INLINE cube_t cubefromarray_single(uint8_t [static 20]);
STATIC bool isconsistent(cube_t);
STATIC bool issolvable(cube_t);
STATIC bool issolved(cube_t);
STATIC bool iserror(cube_t);
STATIC void getcube_fix(int64_t *, int64_t *, int64_t *, int64_t *);
STATIC cube_t getcube(int64_t, int64_t, int64_t, int64_t);
/* This is used only in tests, use SOLVED_CUBE directly everywhere else */
STATIC cube_t
solvedcube(void)
{
return SOLVED_CUBE;
}
STATIC_INLINE cube_t
cubefromarray_ce(uint8_t c[static 8], uint8_t e[static 12])
{
return cubefrompieces(
c[0], c[1], c[2], c[3], c[4], c[5], c[6], c[7],
e[0], e[1], e[2], e[3], e[4], e[5], e[6], e[7],
e[8], e[9], e[10], e[11]);
}
STATIC_INLINE cube_t
cubefromarray_single(uint8_t p[static 20])
{
return cubefrompieces(
p[0], p[1], p[2], p[3], p[4], p[5], p[6], p[7], p[8], p[9], p[10],
p[11], p[12], p[13], p[14], p[15], p[16], p[17], p[18], p[19]);
}
STATIC bool
isconsistent(cube_t cube)
{
uint8_t i, p, e, piece, corner[8], edge[12];
bool found[12];
pieces(&cube, corner, edge);
for (i = 0; i < 12; i++)
found[i] = false;
for (i = 0; i < 12; i++) {
piece = edge[i];
p = piece & PBITS;
e = piece & EOBIT;
if (p >= 12)
goto inconsistent_ep;
if (e != 0 && e != EOBIT)
goto inconsistent_eo;
found[p] = true;
}
for (i = 0; i < 12; i++)
if (!found[i])
goto inconsistent_ep;
for (i = 0; i < 8; i++)
found[i] = false;
for (i = 0; i < 8; i++) {
piece = corner[i];
p = piece & PBITS;
e = piece & COBITS;
if (p >= 8)
goto inconsistent_cp;
if (e != 0 && e != CTWIST_CW && e != CTWIST_CCW)
goto inconsistent_co;
found[p] = true;
}
for (i = 0; i < 8; i++)
if (!found[i])
goto inconsistent_co;
return true;
inconsistent_ep:
LOG("Inconsistent EP\n");
return false;
inconsistent_cp:
LOG("Inconsistent CP\n");
return false;
inconsistent_eo:
LOG("Inconsistent EO\n");
return false;
inconsistent_co:
LOG("Inconsistent CO\n");
return false;
}
STATIC bool
issolvable(cube_t cube)
{
uint8_t i, eo, co, piece, edge[12], corner[8], ep[12], cp[8];
DBG_ASSERT(isconsistent(cube), false,
"issolvable: cube is inconsistent\n");
pieces(&cube, corner, edge);
for (i = 0; i < 12; i++)
ep[i] = edge[i] & PBITS;
for (i = 0; i < 8; i++)
cp[i] = corner[i] & PBITS;
if (permsign(ep, 12) != permsign(cp, 8))
goto issolvable_parity;
eo = 0;
for (i = 0; i < 12; i++) {
piece = edge[i];
eo += (piece & EOBIT) >> EOSHIFT;
}
if (eo % 2 != 0)
goto issolvable_eo;
co = 0;
for (i = 0; i < 8; i++) {
piece = corner[i];
co += (piece & COBITS) >> COSHIFT;
}
if (co % 3 != 0)
goto issolvable_co;
return true;
issolvable_parity:
LOG("EP and CP parities are different\n");
return false;
issolvable_eo:
LOG("Odd number of flipped edges\n");
return false;
issolvable_co:
LOG("Sum of corner orientation is not multiple of 3\n");
return false;
}
bool
issolved(cube_t cube)
{
return equal(cube, SOLVED_CUBE);
}
bool
iserror(cube_t cube)
{
return equal(cube, ZERO_CUBE);
}
STATIC void
getcube_fix(int64_t *ep, int64_t *eo, int64_t *cp, int64_t *co)
{
uint8_t e[12], c[8], coarr[8];
*ep = (*ep % FACT_12 + FACT_12) % FACT_12;
*eo = (*eo % POW_2_11 + POW_2_11) % POW_2_11;
*cp = (*cp % FACT_8 + FACT_8) % FACT_8;
*co = (*cp % POW_3_7 + POW_3_7) % POW_3_7;
indextoperm(*ep, 12, e);
indextoperm(*cp, 8, c);
if (permsign(e, 12) != permsign(c, 8)) {
SWAP(c[0], c[1]);
*cp = permtoindex(c, 8);
sumzerotodigits(*co, 8, 3, coarr);
SWAP(coarr[0], coarr[1]);
*co = digitstosumzero(coarr, 8, 3);
}
}
STATIC cube_t
getcube(int64_t ep, int64_t eo, int64_t cp, int64_t co)
{
uint8_t i, earr[12], carr[8], eoarr[12], coarr[8];
sumzerotodigits(eo, 12, 2, eoarr);
DBG_ASSERT(eoarr[0] != UINT8_ERROR, ZERO_CUBE, "Error making EO");
indextoperm(ep, 12, earr);
DBG_ASSERT(earr[0] != UINT8_ERROR, ZERO_CUBE, "Error making EP");
for (i = 0; i < 12; i++)
earr[i] |= eoarr[i] << EOSHIFT;
sumzerotodigits(co, 8, 3, coarr);
DBG_ASSERT(coarr[0] != UINT8_ERROR, ZERO_CUBE, "Error making CO");
indextoperm(cp, 8, carr);
DBG_ASSERT(carr[0] != UINT8_ERROR, ZERO_CUBE, "Error making CP");
for (i = 0; i < 8; i++)
carr[i] |= coarr[i] << COSHIFT;
return cubefromarray_ce(carr, earr);
}
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