965dadaa
Salvador Abreu
initial commit fr...
|
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
|
/* element-var */
/* element-var(X, y, z) == X[y] = z (0 <= y < |X|) */
static int fd_element_var_filter(fd_constraint this)
{
int length = this->nvariables - 2;
fd_int index, value;
int imax, min, max;
int v;
int i;
// do some filtering...
index = VAR(this, this->nvariables - 2);
// check the index variable
if (_fd_var_del_ge(length, index))
{
if (fd_domain_empty(index))
return FD_NOSOLUTION;
_fd_revise_connected(this, index);
}
value = VAR(this, this->nvariables - 1);
// see if the index is already fixed
if (fd_var_single(index, &v))
{
if (_fd_var_intersect(VAR(this, v), value))
{
if (fd_domain_empty(VAR(this, v)))
return FD_NOSOLUTION;
_fd_revise_connected(this, VAR(this, v));
}
if (_fd_var_intersect(value, VAR(this, v)))
{
if (fd_domain_empty(value))
return FD_NOSOLUTION;
_fd_revise_connected(this, value);
}
return FD_OK;
}
// do some bounds filtering on the value variable
imax = _fd_var_max(index);
min = _fd_var_min(VAR(this, imax));
max = _fd_var_max(VAR(this, imax));
for (i = _fd_var_min(index); i < imax; ++i)
{
int m;
if ((m = _fd_var_min(VAR(this, i))) < min)
min = m;
else if ((m = _fd_var_max(VAR(this, i))) > max)
max = m;
}
if (_fd_var_del_lt(min, value) | _fd_var_del_gt(max, value))
{
if (fd_domain_empty(value))
return FD_NOSOLUTION;
_fd_revise_connected(this, value);
}
// XXX: more...
return FD_OK;
}
static int fd_element_var_propagate2(fd_constraint this, fd_int culprit)
{
int length = this->nvariables - 2;
fd_int index, value;
int i;
// do some filtering...
index = VAR(this, this->nvariables - 2);
value = VAR(this, this->nvariables - 1);
// see if the culprit is the index variable
if (culprit == index)
{
if (fd_var_single(index, &i))
{
if (_fd_var_intersect(VAR(this, i), value))
{
if (fd_domain_empty(VAR(this, i)))
return FD_NOSOLUTION;
_fd_revise_connected(this, VAR(this, i));
}
if (_fd_var_intersect(value, VAR(this, i)))
{
if (fd_domain_empty(value))
return FD_NOSOLUTION;
_fd_revise_connected(this, value);
}
}
return FD_OK;
}
// see if the culprit is the value variable
if (culprit == value)
{
int k;
if (fd_var_single(value, &k))
{
// check which variables have k in their domain
int imax = _fd_var_max(index);
for (i = _fd_var_min(index); i <= imax; ++i)
if (!_fd_var_contains_val(VAR(this, i), k) &&
_fd_var_del_val(i, index))
{
if (fd_domain_empty(index))
return FD_NOSOLUTION;
_fd_revise_connected(NULL, index);
}
}
return FD_OK;
}
// XXX: filter for non-index and non-value variables
return FD_OK;
}
fd_constraint fd_element_var(fd_int *variables, int nvariables, fd_int index,
fd_int value)
{
|