1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
STATIC cube_t solvedcube(void);
STATIC cube_t cubefromarray(uint8_t [static 8], uint8_t [static 12]);
STATIC bool isconsistent(cube_t);
STATIC bool issolvable(cube_t);
STATIC bool issolved(cube_t);
STATIC bool iserror(cube_t);
STATIC void getcube_fix(long long *, long long *, long long *, long long *);
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 cube_t
cubefromarray(uint8_t c[static 8], uint8_t e[static 12])
{
return STATIC_CUBE(
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 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:
inconsistent_cp:
inconsistent_eo:
inconsistent_co:
/* We used to do more logging here, hence the 4 different labels */
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(12, ep) != permsign(8, cp))
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:
issolvable_eo:
issolvable_co:
/* We used to do more logging here, hence the 3 different labels */
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(long long *ep, long long *eo, long long *cp, long long *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(12, e) != permsign(8, c)) {
SWAP(c[0], c[1]);
*cp = permtoindex(8, c);
sumzerotodigits(*co, 8, 3, coarr);
SWAP(coarr[0], coarr[1]);
*co = digitstosumzero(8, coarr, 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(carr, earr);
}
|
