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dekker.one
1/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2/*
3 * Main authors:
4 * Guido Tack <tack@gecode.org>
5 *
6 * Copyright:
7 * Guido Tack, 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
34#ifndef GECODE_GIST_NODE_HH
35#define GECODE_GIST_NODE_HH
36
37#include <gecode/kernel.hh>
38
39#include <QHash>
40#include <QString>
41
42namespace Gecode { namespace Gist {
43
44 class VisualNode;
45
46 /// Node allocator
47 template<class T>
48 class NodeAllocatorBase {
49 private:
50 /// Size of each block of nodes
51 static const int NodeBlockSize = 1<<14;
52 /// Blocks of nodes
53 class Block {
54 public:
55 /// The actual nodes
56 T b[NodeBlockSize];
57 /// The index of the best known previous solution for each node
58 int best[NodeBlockSize];
59 };
60 /// Array of blocks
61 Block** b;
62 /// Size of the array
63 int n;
64 /// Current block number
65 int cur_b;
66 /// Current node number in current block
67 int cur_t;
68 /// Allocate new block, potentially reallocate block array
69 void allocate(void);
70 /// Flag whether search uses branch-and-bound
71 bool _bab;
72 /// Hash table mapping nodes to label text
73 QHash<T*,QString> labels;
74 public:
75 /// Constructor
76 NodeAllocatorBase(bool bab);
77 /// Destructor
78 ~NodeAllocatorBase(void);
79 /// Allocate new node with parent \a p
80 int allocate(int p);
81 /// Allocate new root node for space \a root
82 int allocate(Space* root);
83 /// Return node for index \a i
84 T* operator [](int i) const;
85 /// Return index of best node before \a i
86 T* best(int i) const;
87 /// Set index of best node before \a i to \a b
88 void setBest(int i, int b);
89 /// Return branch-and-bound flag
90 bool bab(void) const;
91 /// Return branching label flag
92 bool showLabels(void) const;
93 /// Set branching label flag
94 void showLabels(bool b);
95 /// Return whether node \a n has a label
96 bool hasLabel(T* n) const;
97 /// Set label of node \a n to \a l
98 void setLabel(T* n, const QString& l);
99 /// Remove label of node \a n
100 void clearLabel(T* n);
101 /// Get label of node \a n
102 QString getLabel(T* n) const;
103 };
104
105 /// \brief Base class for nodes of the search tree
106 class Node {
107 private:
108 /// Tags that are used to encode the number of children
109 enum {
110 UNDET, //< Number of children not determined
111 LEAF, //< Leaf node
112 TWO_CHILDREN, //< Node with at most two children
113 MORE_CHILDREN //< Node with more than two children
114 };
115
116 /// The children, or in case there are at most two, the first child
117 void* childrenOrFirstChild;
118
119 /** The number of children, in case it is greater than 2, or the first
120 * child (if negative)
121 */
122 int noOfChildren;
123
124 /// The parent of this node, or nullptr for the root
125 int parent;
126
127 /// Read the tag of childrenOrFirstChild
128 unsigned int getTag(void) const;
129 /// Set the tag of childrenOrFirstChild
130 void setTag(unsigned int tag);
131 /// Return childrenOrFirstChild without tag
132 void* getPtr(void) const;
133 /// Return childrenOrFirstChild as integer
134 int getFirstChild(void) const;
135
136 protected:
137 /// Return whether this node is undetermined
138 bool isUndetermined(void) const;
139
140 /// Return index of child no \a n
141 int getChild(int n) const;
142 public:
143 typedef NodeAllocatorBase<VisualNode> NodeAllocator;
144
145 /// Construct node with parent \a p
146 Node(int p, bool failed = false);
147
148 /// Return the parent
149 int getParent(void) const;
150 /// Return the parent
151 VisualNode* getParent(const NodeAllocator& na) const;
152 /// Return child no \a n
153 VisualNode* getChild(const NodeAllocator& na, int n) const;
154
155 /// Return index of this node
156 int getIndex(const NodeAllocator& na) const;
157
158 /// Check if this node is the root of a tree
159 bool isRoot(void) const;
160
161 /// Set the number of children to \a n and initialize children
162 void setNumberOfChildren(unsigned int n, NodeAllocator& na);
163
164 /// Return the number of children
165 unsigned int getNumberOfChildren(void) const;
166
167 };
168
169}}
170
171#endif
172
173// STATISTICS: gist-any