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cutoff.hpp
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1/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2/*
3 * Main authors:
4 * Guido Tack <tack@gecode.org>
5 *
6 * Contributing authors:
7 * Christian Schulte <schulte@gecode.org>
8 *
9 * Copyright:
10 * Christian Schulte, 2013
11 * Guido Tack, 2013
12 *
13 * This file is part of Gecode, the generic constraint
14 * development environment:
15 * http://www.gecode.org
16 *
17 * Permission is hereby granted, free of charge, to any person obtaining
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37
38namespace Gecode { namespace Search {
39
44
45
47 CutoffConstant::CutoffConstant(unsigned long int c0)
48 : c(c0) {}
49
50
52 CutoffLinear::CutoffLinear(unsigned long int s)
53 : scale(s), n(0) {}
54
55
57 CutoffLuby::CutoffLuby(unsigned long int scale0)
58 : i(1U), scale(scale0) {}
59 forceinline unsigned long int
60 CutoffLuby::log(unsigned long int i) {
61 if (i == 1U)
62 return 0U;
63 unsigned long int exp = 0U;
64 while ( (i >> (++exp)) > 1U ) {}
65 return exp;
66 }
67 forceinline unsigned long int
68 CutoffLuby::luby(unsigned long int i) {
69 while (true) {
70 if (i <= n_start)
71 return start[i-1];
72 unsigned long int l = log(i);
73 if (i == (1U<<(l+1))-1)
74 return 1UL<<l;
75 i=i-(1U<<l)+1;
76 }
78 return 0;
79 }
80
81
83 CutoffGeometric::CutoffGeometric(unsigned long int scale0, double base0)
84 : n(1.0), scale(static_cast<double>(scale0)), base(base0) {}
85
86
88 CutoffRandom::CutoffRandom(unsigned int seed,
89 unsigned long int min0,
90 unsigned long int max0,
91 unsigned long int n0)
92 : rnd(seed), min(min0), n(n0 == 0 ? (max0-min+1U) : n0),
93 step(std::max(1UL,
94 static_cast<unsigned long int>((max0-min0+1U)/n))) {
95 cur = ++(*this);
96 }
97
98
100 CutoffAppend::CutoffAppend(Cutoff* d1, unsigned long int n0, Cutoff* d2)
101 : c1(d1), c2(d2), n(n0) {}
104 delete c1; delete c2;
105 }
106
107
110 : c1(d1), c2(d2) {}
113 delete c1; delete c2;
114 }
115
116
118 CutoffRepeat::CutoffRepeat(Cutoff* c1, unsigned long int n0)
119 : c(c1), i(0), n(n0) {
120 cutoff = (*c)();
121 }
124 delete c;
125 }
126
127}}
128
129// STATISTICS: search-other
NNF * l
Left subtree.
int n
Number of negative literals for node type.
Cutoff * c1
First cutoff generators.
Definition search.hh:639
virtual ~CutoffAppend(void)
Destructor.
Definition cutoff.hpp:103
Cutoff * c2
Second cutoff generators.
Definition search.hh:641
CutoffAppend(Cutoff *c1, unsigned long int n, Cutoff *c2)
Constructor.
Definition cutoff.hpp:100
CutoffConstant(unsigned long int c)
Constructor.
Definition cutoff.hpp:47
CutoffGeometric(unsigned long int scale, double base)
Constructor.
Definition cutoff.hpp:83
CutoffLinear(unsigned long int scale)
Constructor.
Definition cutoff.hpp:52
static unsigned long int luby(unsigned long int i)
Compute Luby number for step i.
Definition cutoff.hpp:68
static const unsigned long int n_start
Number of pre-computed luby values.
Definition search.hh:568
CutoffLuby(unsigned long int scale)
Constructor.
Definition cutoff.hpp:57
static unsigned long int log(unsigned long int i)
Compute binary logarithm of i.
Definition cutoff.hpp:60
unsigned long int i
Iteration number.
Definition search.hh:564
static unsigned long int start[n_start]
Precomputed luby-values.
Definition search.hh:570
virtual ~CutoffMerge(void)
Destructor.
Definition cutoff.hpp:112
Cutoff * c1
First cutoff generator.
Definition search.hh:662
Cutoff * c2
Second cutoff generator.
Definition search.hh:664
CutoffMerge(Cutoff *c1, Cutoff *c2)
Constructor.
Definition cutoff.hpp:109
unsigned long int cur
Current value.
Definition search.hh:620
CutoffRandom(unsigned int seed, unsigned long int min, unsigned long int max, unsigned long int n)
Constructor.
Definition cutoff.hpp:88
CutoffRepeat(Cutoff *c, unsigned long int n)
Constructor.
Definition cutoff.hpp:118
Cutoff * c
Actual cutoff generator.
Definition search.hh:683
virtual ~CutoffRepeat(void)
Destructor.
Definition cutoff.hpp:123
Base class for cutoff generators for restart-based meta engine.
Definition search.hh:472
virtual ~Cutoff(void)
Destructor.
Definition cutoff.hpp:43
Cutoff(void)
Default constructor.
Definition cutoff.hpp:41
Gecode toplevel namespace
void min(Home home, FloatVar x0, FloatVar x1, FloatVar x2)
Post propagator for .
void exp(Home home, FloatVar x0, FloatVar x1)
Post propagator for .
void max(Home home, FloatVar x0, FloatVar x1, FloatVar x2)
Post propagator for .
#define forceinline
Definition config.hpp:187
#define GECODE_NEVER
Assert that this command is never executed.
Definition macros.hpp:56