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opt-prop.hpp
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1 /* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2 /*
3  * Main authors:
4  * Christian Schulte <schulte@gecode.org>
5  * Guido Tack <tack@gecode.org>
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7  * Copyright:
8  * Christian Schulte, 2009
9  * Guido Tack, 2010
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11  * Last modified:
12  * $Date: 2011-07-14 06:44:50 +1000 (Thu, 14 Jul 2011) $ by $Author: tack $
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39 
40 #include <algorithm>
41 
42 namespace Gecode { namespace Int { namespace Cumulative {
43 
44  template<class OptTask, class Cap>
47  : TaskProp<OptTask,Int::PC_INT_DOM>(home,t), c(c0) {
48  c.subscribe(home,*this,PC_INT_BND);
49  }
50 
51  template<class OptTask, class Cap>
55  : TaskProp<OptTask,Int::PC_INT_DOM>(home,shared,p) {
56  c.update(home,shared,p.c);
57  }
58 
59  template<class OptTask, class Cap>
62  // Capacity must be nonnegative
63  GECODE_ME_CHECK(c.gq(home, 0));
64  // Check for overload by single task and remove excluded tasks
65  int n=t.size(), m=0;
66  for (int i=n; i--; ) {
67  if (t[i].c() > c.max())
68  GECODE_ME_CHECK(t[i].excluded(home));
69  if (t[i].excluded())
70  t[i]=t[--n];
71  else if (t[i].mandatory())
72  m++;
73  }
74  t.size(n);
75  if (t.size() < 2) {
76  if (t.size() == 1) {
77  if (t[0].mandatory()) {
78  GECODE_ME_CHECK(c.gq(home, t[0].c()));
79  return ES_OK;
80  } else if (c.min() >= t[0].c()) {
81  return ES_OK;
82  }
83  } else {
84  return ES_OK;
85  }
86  }
87  if (c.assigned() && c.val()==1) {
89  for (int i=t.size(); i--; )
90  mt[i]=t[i];
92  ::post(home,mt);
93  }
94  if (m == t.size()) {
96  for (int i=m; i--; )
97  mt[i].init(t[i]);
99  ::post(home,c,mt);
100  }
101  (void) new (home) OptProp<OptTask,Cap>(home,c,t);
102  return ES_OK;
103  }
104 
105  template<class OptTask, class Cap>
106  Actor*
107  OptProp<OptTask,Cap>::copy(Space& home, bool share) {
108  return new (home) OptProp<OptTask,Cap>(home,share,*this);
109  }
110 
111  template<class OptTask, class Cap>
112  forceinline size_t
115  c.cancel(home,*this,PC_INT_BND);
116  return sizeof(*this);
117  }
118 
119  template<class OptTask, class Cap>
120  ExecStatus
122  // Did one of the Boolean views change?
124  GECODE_ES_CHECK((purge<OptTask,Int::PC_INT_DOM>(home,*this,t,c)));
125  // Only bounds changes?
126  if (Int::IntView::me(med) != Int::ME_INT_DOM)
127  GECODE_ES_CHECK(overload(home,c.max(),t));
128 
129  bool subsumed;
130  GECODE_ES_CHECK(basic(home,subsumed,c,t));
131  if (subsumed)
132  return home.ES_SUBSUMED(*this);
133 
134  // Partition into mandatory and optional activities
135  int n = t.size();
136  int i=0, j=n-1;
137  while (true) {
138  while ((i < n) && t[i].mandatory()) i++;
139  while ((j >= 0) && !t[j].mandatory()) j--;
140  if (i >= j) break;
141  std::swap(t[i],t[j]);
142  }
143 
144  if (i > 1) {
145  // Truncate array to only contain mandatory tasks
146  t.size(i);
147  GECODE_ES_CHECK(edgefinding(home,c.max(),t));
148  // Restore to also include optional tasks
149  t.size(n);
150  }
151 
152  if (Cap::varderived() && c.assigned() && c.val()==1) {
153  // Check that tasks do not overload resource
154  for (int i=t.size(); i--; )
155  if (t[i].c() > 1)
156  GECODE_ME_CHECK(t[i].excluded(home));
157  // Rewrite to unary resource constraint
159  for (int i=t.size(); i--;)
160  ut[i]=t[i];
161  GECODE_REWRITE(*this,
163  ::post(home(*this),ut)));
164  } else {
165  return ES_NOFIX;
166  }
167  }
168 
169 }}}
170 
171 // STATISTICS: int-prop