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
|
// Range v3 library
//
// Copyright Eric Niebler 2013-present
//
// Use, modification and distribution is subject to the
// Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// Project home: https://github.com/ericniebler/range-v3
//
#include <chrono>
#include <iostream>
#include <random>
#include <range/v3/all.hpp>
RANGES_DIAGNOSTIC_IGNORE_SIGN_CONVERSION
class timer
{
public:
using clock_t = std::chrono::high_resolution_clock;
using duration_t = clock_t::time_point::duration;
timer()
{
reset();
}
void reset()
{
start_ = clock_t::now();
}
duration_t elapsed() const
{
return clock_t::now() - start_;
}
friend std::ostream &operator<<(std::ostream &sout, timer const &t)
{
return sout << t.elapsed().count() << "ms";
}
private:
clock_t::time_point start_;
};
template<typename D>
std::chrono::milliseconds::rep to_millis(D d) {
return std::chrono::duration_cast<std::chrono::milliseconds>(d).count();
}
template<typename It>
struct forward_iterator
{
It it_;
public:
typedef std::forward_iterator_tag iterator_category;
typedef typename std::iterator_traits<It>::value_type value_type;
typedef typename std::iterator_traits<It>::difference_type difference_type;
typedef It pointer;
typedef typename std::iterator_traits<It>::reference reference;
forward_iterator() = default;
explicit forward_iterator(It it) : it_(std::move(it)) {}
reference operator*() const {return *it_;}
pointer operator->() const {return it_;}
forward_iterator& operator++() {++it_; return *this;}
forward_iterator operator++(int)
{forward_iterator tmp(*this); ++(*this); return tmp;}
friend bool operator==(const forward_iterator& x, const forward_iterator& y)
{return x.it_ == y.it_;}
friend bool operator!=(const forward_iterator& x, const forward_iterator& y)
{return !(x == y);}
};
template<typename I, typename V2>
I upper_bound_n(I first, typename std::iterator_traits<I>::difference_type d, V2 const &val)
{
while(0 != d)
{
auto half = d / 2;
auto middle = std::next(first, half);
if(val < *middle)
d = half;
else
{
first = ++middle;
d -= half + 1;
}
}
return first;
}
template<typename I>
void insertion_sort_n(I first, typename std::iterator_traits<I>::difference_type n)
{
auto m = 0;
for(auto it = first; m != n; ++it, ++m)
{
auto insertion = upper_bound_n(first, m, *it);
ranges::rotate(insertion, it, std::next(it));
}
}
template<typename I, typename S>
void insertion_sort(I first, S last)
{
for(auto it = first; it != last; ++it)
{
auto insertion = ranges::upper_bound(first, it, *it);
ranges::rotate(insertion, it, std::next(it));
}
}
template<typename Rng>
void insertion_sort(Rng && rng)
{
::insertion_sort(std::begin(rng), std::end(rng));
}
std::unique_ptr<int> data(int i)
{
std::unique_ptr<int> a(new int[i]);
auto rng = ranges::views::counted(a.get(), i);
ranges::iota(rng, 0);
return a;
}
template<typename Gen>
void shuffle(int *a, int i, Gen && rand)
{
auto rng = ranges::views::counted(a, i);
rng |= ranges::actions::shuffle(std::forward<Gen>(rand));
}
constexpr int cloops = 3;
template<typename I>
void benchmark_n(int i)
{
std::mt19937 gen;
auto a = data(i);
timer::duration_t ms = {};
for(int j = 0; j < cloops; ++j)
{
::shuffle(a.get(), i, gen);
timer t;
insertion_sort_n(I{a.get()}, i);
ms += t.elapsed();
}
std::cout << to_millis(ms/cloops) << std::endl;
}
template<typename I>
void benchmark_counted(int i)
{
std::mt19937 gen;
auto a = data(i);
timer::duration_t ms = {};
for(int j = 0; j < cloops; ++j)
{
::shuffle(a.get(), i, gen);
timer t;
insertion_sort(ranges::views::counted(I{a.get()}, i));
ms += t.elapsed();
}
std::cout << to_millis(ms/cloops) << std::endl;
}
int main(int argc, char *argv[])
{
if(argc < 2)
return -1;
int i = std::atoi(argv[1]);
std::cout << "insertion_sort_n (random-access) : ";
benchmark_n<int*>(i);
std::cout << "insertion_sort (random-access) : ";
benchmark_counted<int*>(i);
std::cout << "\n";
std::cout << "insertion_sort_n (forward) : ";
benchmark_n<forward_iterator<int*>>(i);
std::cout << "insertion_sort (forward) : ";
benchmark_counted<forward_iterator<int*>>(i);
}
|
