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dekker.one
1/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2/*
3 * Main authors:
4 * Christian Schulte <schulte@gecode.org>
5 *
6 * Copyright:
7 * Christian Schulte, 2006
8 *
9 * This file is part of Gecode, the generic constraint
10 * development environment:
11 * http://www.gecode.org
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining
14 * a copy of this software and associated documentation files (the
15 * "Software"), to deal in the Software without restriction, including
16 * without limitation the rights to use, copy, modify, merge, publish,
17 * distribute, sublicense, and/or sell copies of the Software, and to
18 * permit persons to whom the Software is furnished to do so, subject to
19 * the following conditions:
20 *
21 * The above copyright notice and this permission notice shall be
22 * included in all copies or substantial portions of the Software.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
28 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
29 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
30 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
31 *
32 */
33
34namespace Gecode { namespace Int { namespace Count {
35
36 template<class VX, class VY>
37 forceinline
38 GqInt<VX,VY>::GqInt(Home home, ViewArray<VX>& x, int n_s, VY y, int c)
39 : IntBase<VX,VY>(home,x,n_s,y,c) {}
40
41 template<class VX, class VY>
42 ExecStatus
43 GqInt<VX,VY>::post(Home home, ViewArray<VX>& x, VY y, int c) {
44 // Eliminate decided views
45 int n_x = x.size();
46 for (int i=n_x; i--; )
47 switch (holds(x[i],y)) {
48 case RT_FALSE:
49 x[i] = x[--n_x]; break;
50 case RT_TRUE:
51 x[i] = x[--n_x]; c--; break;
52 case RT_MAYBE:
53 break;
54 default:
55 GECODE_NEVER;
56 }
57 x.size(n_x);
58 // RHS too large
59 if (n_x < c)
60 return ES_FAILED;
61 // Whatever the x[i] take for values, the inequality is subsumed
62 if (c <= 0)
63 return ES_OK;
64 // All views must be equal
65 if (c == n_x)
66 return post_true(home,x,y);
67 (void) new (home) GqInt<VX,VY>(home,x,c+1,y,c);
68 return ES_OK;
69 }
70
71 template<class VX, class VY>
72 forceinline
73 GqInt<VX,VY>::GqInt(Space& home, GqInt<VX,VY>& p)
74 : IntBase<VX,VY>(home,p) {}
75
76 template<class VX, class VY>
77 Actor*
78 GqInt<VX,VY>::copy(Space& home) {
79 return new (home) GqInt<VX,VY>(home,*this);
80 }
81
82 template<class VX, class VY>
83 ExecStatus
84 GqInt<VX,VY>::propagate(Space& home, const ModEventDelta&) {
85 // Eliminate decided views from subscribed views
86 int n_x = x.size();
87 for (int i=n_s; i--; )
88 switch (holds(x[i],y)) {
89 case RT_FALSE:
90 x[i].cancel(home,*this,PC_INT_DOM);
91 x[i]=x[--n_s]; x[n_s]=x[--n_x];
92 break;
93 case RT_TRUE:
94 x[i].cancel(home,*this,PC_INT_DOM);
95 x[i]=x[--n_s]; x[n_s]=x[--n_x]; c--;
96 break;
97 case RT_MAYBE:
98 break;
99 default:
100 GECODE_NEVER;
101 }
102 x.size(n_x);
103 if (n_x < c)
104 return ES_FAILED;
105 if (c <= 0)
106 return home.ES_SUBSUMED(*this);
107 // Eliminate decided views from unsubscribed views
108 for (int i=n_x; i-- > n_s; )
109 switch (holds(x[i],y)) {
110 case RT_FALSE: x[i]=x[--n_x]; break;
111 case RT_TRUE: x[i]=x[--n_x]; c--; break;
112 case RT_MAYBE: break;
113 default: GECODE_NEVER;
114 }
115 x.size(n_x);
116 if (n_x < c)
117 return ES_FAILED;
118 if (c <= 0)
119 return home.ES_SUBSUMED(*this);
120 if (c == n_x) {
121 // All views must be equal
122 GECODE_ES_CHECK(post_true(home,x,y));
123 return home.ES_SUBSUMED(*this);
124 }
125 // Now, there must be new subscriptions from x[n_s] up to x[c+1]
126 while (n_s <= c)
127 x[n_s++].subscribe(home,*this,PC_INT_DOM,false);
128 return ES_FIX;
129 }
130
131}}}
132
133// STATISTICS: int-prop