
Bounds consistent distinct propagator. More...
#include <distinct.hh>
Public Member Functions | |
| virtual ExecStatus | propagate (Space &home, const ModEventDelta &med) |
| Perform propagation. | |
| virtual PropCost | cost (const Space &home, const ModEventDelta &med) const |
| Cost function. | |
| virtual void | reschedule (Space &home) |
| Schedule function. | |
| virtual Actor * | copy (Space &home) |
| Copy propagator during cloning. | |
| virtual size_t | dispose (Space &home) |
| Destructor. | |
| ModEventDelta | modeventdelta (void) const |
| Return the modification event delta. | |
| virtual ExecStatus | advise (Space &home, Advisor &a, const Delta &d) |
| Advise function. | |
| virtual void | advise (Space &home, Advisor &a) |
| Run advisor a to be run on failure in failed space. | |
| double | afc (void) const |
| Return the accumlated failure count. | |
| unsigned int | id (void) const |
| Return propagator id. | |
| PropagatorGroup | group (void) const |
| Return group propagator belongs to. | |
| void | group (PropagatorGroup g) |
| Add propagator to group g. | |
| bool | disabled (void) const |
| Whether propagator is currently disabled. | |
| virtual | ~Actor (void) |
| To avoid warnings. | |
Static Public Member Functions | |
| static ExecStatus | post (Home home, ViewArray< View > &x) |
| Post propagator for view array x. | |
| static void * | operator new (size_t s, Space &home) |
| Allocate memory from space. | |
| static void | operator delete (void *p, Space &home) |
| No-op for exceptions. | |
| static void * | operator new (size_t s) |
| Not used. | |
| static void | operator delete (void *p) |
| Not used. | |
Protected Member Functions | |
| Bnd (Home home, ViewArray< View > &x) | |
| Constructor for posting. | |
| Bnd (Space &home, Bnd< View > &p) | |
| Constructor for cloning p. | |
Protected Member Functions inherited from Gecode::Propagator | |
| Propagator (Home home) | |
| Constructor for posting. | |
| Propagator (Space &home, Propagator &p) | |
| Constructor for cloning p. | |
| Propagator * | fwd (void) const |
| Return forwarding pointer during copying. | |
| Kernel::GPI::Info & | gpi (void) |
| Provide access to global propagator information. | |
Protected Attributes | |
| ViewArray< View > | x |
| Views on which to perform bounds-propagation. | |
| ViewArray< View > | y |
Views on which to perform value-propagation (subset of x) | |
| int | min_x |
| Minimum (approximation) of view in x. | |
| int | max_x |
| Maximum (approximation) of view in x. | |
Bounds consistent distinct propagator.
The propagator uses staging: first it uses naive value-based propagation and only then uses bounds consistent propagation. Due to using naive value-based propagation, the propagator might actually achieve stronger consistency than just bounds consistency.
The algorithm is taken from: A. Lopez-Ortiz, C.-G. Quimper, J. Tromp, and P. van Beek. A fast and simple algorithm for bounds consistency of the alldifferent constraint. IJCAI-2003.
This implementation uses the code that is provided by Peter Van Beek: http://ai.uwaterloo.ca/~vanbeek/software/software.html The code (originally by John Tromp) here has only been slightly modified to fit Gecode (taking idempotent/non-idempotent propagation into account) and uses a more efficient layout of datastructures (keeping the number of different arrays small).
Requires
Definition at line 152 of file distinct.hh.
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Cost function.
If in stage for naive value propagation, the cost is low linear. Otherwise it is low quadratic.
Implements Gecode::Propagator.
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Views on which to perform bounds-propagation.
Definition at line 155 of file distinct.hh.
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Views on which to perform value-propagation (subset of x)
Definition at line 157 of file distinct.hh.
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Minimum (approximation) of view in x.
Definition at line 159 of file distinct.hh.
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Maximum (approximation) of view in x.
Definition at line 161 of file distinct.hh.