/
qpriorityqueue.h
253 lines (217 loc) · 6.28 KB
/
qpriorityqueue.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
/****************************************************************************
**
** Copyright (C) 2015 Corentin Chary <corentin.chary@gmail.cm>
**
** This file could be part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef QPRIORITY_QUEUE_H
#define QPRIORITY_QUEUE_H
#include <QtCore/qalgorithms.h>
QT_BEGIN_HEADER
QT_BEGIN_NAMESPACE
QT_MODULE(Core)
template <class T> class QList;
#ifndef QT_NO_STL
#include <queue>
#include <vector>
#else
/* Fallback class used when stl is not available */
template <class T, typename LessThan = qLess < T > >
class QPriorityQueuePrivate {
public:
inline QPriorityQueuePrivate(LessThan l) : lessThan(l), d() {}
inline ~QPriorityQueuePrivate() {}
inline void clear() { return d.clear(); }
inline int size() const { return d.size(); }
inline bool empty() const { return d.empty(); }
inline T &top() { return d.front(); }
void pop();
void push(const T &value);
private:
inline int parent(int i) {
return (i - 1) / 2;
}
inline int leftChild(int i) {
return 2 * i + 1;
}
inline int rightChild(int i) {
return 2 * i + 2;
}
LessThan lessThan;
QList < T > d;
};
#endif
template <class T, typename LessThan = qLess < T > >
class Q_CORE_EXPORT QPriorityQueue
{
public:
inline QPriorityQueue(LessThan l = qLess < T >())
: lessThan(l), d(lessThan) { }
inline QPriorityQueue(const QPriorityQueue<T> &q)
: lessThan(q.lessThan), d(q.d) { }
inline ~QPriorityQueue() { }
QPriorityQueue<T> &operator=(const QPriorityQueue<T> &q) {
d = q.d; return *this;
}
inline int size() const { return d.size(); }
inline bool isEmpty() const { return empty(); }
// like qlist
void clear();
void append(const T &t) { return enqueue(t); }
void append(const QList<T> &t);
T takeFirst() { return dequeue(); }
inline int length() const { return size(); } // Same as count()
inline T& first() { return head(); }
inline const T& first() const { return head(); }
inline void removeFirst() { pop(); }
inline bool startsWith(const T &t) const
{ return !isEmpty() && first() == t; }
// like qqueue
inline void enqueue(const T &t) { push(t); }
inline T dequeue() { T t = d.top(); d.pop(); return t; }
inline T &head() { top(); }
inline const T &head() const { top(); }
// stl compatibility
typedef int size_type;
typedef T value_type;
inline bool empty() const { return d.empty(); }
inline const value_type& top() { Q_ASSERT(!isEmpty()); return d.top(); }
inline void push(const value_type& x) { return d.push(x); }
inline void pop() { Q_ASSERT(!isEmpty()); d.pop(); }
// comfort
inline QPriorityQueue<T> &operator+=(const T &t) {
enqueue(t); return *this;
}
inline QPriorityQueue<T> &operator<< (const T &t) {
enqueue(t); return *this;
}
inline QPriorityQueue<T> &operator>> (T &t) {
t = d.top(); d.pop(); return *this;
}
#ifndef QT_NO_STL
static inline QPriorityQueue<T>fromStdPriorityQueue(
const std::priority_queue<T> &q) {
QPriorityQueue<T> tmp; tmp.d = q; return tmp;
}
inline std::priority_queue<T> toStdPriorityQueue() const {
return d;
}
#endif
private:
LessThan lessThan;
#ifndef QT_NO_STL
std::priority_queue <T, std::vector < T >, LessThan> d;
#else
QPriorityQueuePrivate <T> d;
#endif
};
#ifndef QT_NO_STL
template <typename T, typename LessThan>
Q_INLINE_TEMPLATE void QPriorityQueue<T, LessThan>::clear()
{
d = std::priority_queue<T>(lessThan);
}
#else
template <typename T, typename LessThan>
Q_INLINE_TEMPLATE void QPriorityQueue<T, LessThan>::clear()
{
d.clear();
}
#endif
template <typename T, typename LessThan>
Q_OUTOFLINE_TEMPLATE void QPriorityQueue<T, LessThan>::append(const QList<T> &t)
{
foreach (T & e, t)
push(e);
}
// Re-implement std::priority_queue if STL not available, probably
// less efficient.
#ifdef QT_NO_STL
/*!
* Pop an element from the queue and reorder it using an
* inlined binary heap.
*
* \internal
*/
template <typename T, typename LessThan>
Q_OUTOFLINE_TEMPLATE void QPriorityQueuePrivate<T, LessThan>::pop()
{
int i = 0;
ssize_t size = d.size();;
if(!size)
return;
if(size == 1)
return d.clear();
d[0] = d.takeLast();
while(i < size - 1) {
int left = leftChild(i);
int right = rightChild(i);
bool validLeft = left < size;
bool validRight = right < size;
if(validLeft && lessThan(d.at(i), d.at(left)))
if(validRight && !lessThan(d.at(right), d.at(left))) {
d.swap(i, right);
i = right;
} else {
d.swap(i, left);
i = left;
}
else if(validRight && lessThan(d.at(i), d.at(right))) {
d.swap(i, right);
i = right;
}
else
break;
}
}
/*!
* Push an element with a given priority to the right place.
*
* \internal
*/
template <typename T, typename LessThan>
Q_OUTOFLINE_TEMPLATE void QPriorityQueuePrivate<T, LessThan>::push(const T &value)
{
int i = d.size();
d.append(value);
while(i != 0 && !lessThan(d.at(i), d.at(parent(i)))) {
d.swap(i, parent(i));
i = parent(i);
}
}
#endif
QT_END_NAMESPACE
QT_END_HEADER
#endif // QPRIORITY_QUEUE_H