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
|
#pragma once
#if defined __GLIBCXX__ && defined _GLIBCXX_DEBUG
#include <utility>
#include <iterator>
// regular STL implementation stripped of debug code
namespace floormat::Heap {
template<typename It, typename Compare>
inline void _push_heap(It first,
std::iter_difference_t<It> holeIndex,
std::iter_difference_t<It> topIndex,
std::iter_value_t<It> value,
Compare& comp)
{
std::iter_difference_t<It> parent = (holeIndex - 1) / 2;
while (holeIndex > topIndex && comp(*(first + parent), value))
{
*(first + holeIndex) = std::move(*(first + parent));
holeIndex = parent;
parent = (holeIndex - 1) / 2;
}
*(first + holeIndex) = std::move(value);
}
template<typename It, typename Compare>
void push_heap(It first, It last, Compare comp)
{
_push_heap(first,
std::iter_difference_t<It>((last - first) - 1),
std::iter_difference_t<It>(0),
std::move(*(last - 1)),
comp);
}
template<typename It, typename Compare>
void _adjust_heap(It first,
std::iter_difference_t<It> holeIndex,
std::iter_difference_t<It> len,
std::iter_value_t<It> value,
Compare& comp)
{
const auto topIndex = holeIndex;
auto secondChild = holeIndex;
while (secondChild < (len - 1) / 2)
{
secondChild = 2 * (secondChild + 1);
if (comp(*(first + secondChild), *(first + (secondChild - 1))))
secondChild--;
*(first + holeIndex) = std::move(*(first + secondChild));
holeIndex = secondChild;
}
if ((len & 1) == 0 && secondChild == (len - 2) / 2)
{
secondChild = 2 * (secondChild + 1);
*(first + holeIndex) = std::move(*(first + (secondChild - 1)));
holeIndex = secondChild - 1;
}
_push_heap(first, holeIndex, topIndex, std::move(value), comp);
}
template<typename It, typename Compare>
void pop_heap(It first, It last, Compare comp)
{
if (last - first > 1)
{
--last;
auto value = std::move(*last);
*last = std::move(*first);
_adjust_heap(first,
std::iter_difference_t<It>(0),
std::iter_difference_t<It>(last - first),
std::move(value),
comp);
}
}
} // namespace floormat::Heap
#else
#include <algorithm>
namespace floormat::Heap {
using std::push_heap;
using std::pop_heap;
} // namespace floormat::Heap
#endif
|
