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1// -*- C++ -*-
2//===---------------------------- numeric ---------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_NUMERIC
12#define _LIBCPP_NUMERIC
13
14/*
15    numeric synopsis
16
17namespace std
18{
19
20template <class InputIterator, class T>
21    T
22    accumulate(InputIterator first, InputIterator last, T init);
23
24template <class InputIterator, class T, class BinaryOperation>
25    T
26    accumulate(InputIterator first, InputIterator last, T init, BinaryOperation binary_op);
27
28template <class InputIterator1, class InputIterator2, class T>
29    T
30    inner_product(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, T init);
31
32template <class InputIterator1, class InputIterator2, class T, class BinaryOperation1, class BinaryOperation2>
33    T
34    inner_product(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2,
35                  T init, BinaryOperation1 binary_op1, BinaryOperation2 binary_op2);
36
37template <class InputIterator, class OutputIterator>
38    OutputIterator
39    partial_sum(InputIterator first, InputIterator last, OutputIterator result);
40
41template <class InputIterator, class OutputIterator, class BinaryOperation>
42    OutputIterator
43    partial_sum(InputIterator first, InputIterator last, OutputIterator result, BinaryOperation binary_op);
44
45template <class InputIterator, class OutputIterator>
46    OutputIterator
47    adjacent_difference(InputIterator first, InputIterator last, OutputIterator result);
48
49template <class InputIterator, class OutputIterator, class BinaryOperation>
50    OutputIterator
51    adjacent_difference(InputIterator first, InputIterator last, OutputIterator result, BinaryOperation binary_op);
52
53template <class ForwardIterator, class T>
54    void iota(ForwardIterator first, ForwardIterator last, T value);
55
56template <class M, class N>
57    constexpr common_type_t<M,N> gcd(M m, N n);    // C++17
58
59template <class M, class N>
60    constexpr common_type_t<M,N> lcm(M m, N n);    // C++17
61
62}  // std
63
64*/
65
66#include <__config>
67#include <iterator>
68#include <limits> // for numeric_limits
69
70#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
71#pragma GCC system_header
72#endif
73
74_LIBCPP_BEGIN_NAMESPACE_STD
75
76template <class _InputIterator, class _Tp>
77inline _LIBCPP_INLINE_VISIBILITY
78_Tp
79accumulate(_InputIterator __first, _InputIterator __last, _Tp __init)
80{
81    for (; __first != __last; ++__first)
82        __init = __init + *__first;
83    return __init;
84}
85
86template <class _InputIterator, class _Tp, class _BinaryOperation>
87inline _LIBCPP_INLINE_VISIBILITY
88_Tp
89accumulate(_InputIterator __first, _InputIterator __last, _Tp __init, _BinaryOperation __binary_op)
90{
91    for (; __first != __last; ++__first)
92        __init = __binary_op(__init, *__first);
93    return __init;
94}
95
96template <class _InputIterator1, class _InputIterator2, class _Tp>
97inline _LIBCPP_INLINE_VISIBILITY
98_Tp
99inner_product(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _Tp __init)
100{
101    for (; __first1 != __last1; ++__first1, (void) ++__first2)
102        __init = __init + *__first1 * *__first2;
103    return __init;
104}
105
106template <class _InputIterator1, class _InputIterator2, class _Tp, class _BinaryOperation1, class _BinaryOperation2>
107inline _LIBCPP_INLINE_VISIBILITY
108_Tp
109inner_product(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2,
110              _Tp __init, _BinaryOperation1 __binary_op1, _BinaryOperation2 __binary_op2)
111{
112    for (; __first1 != __last1; ++__first1, (void) ++__first2)
113        __init = __binary_op1(__init, __binary_op2(*__first1, *__first2));
114    return __init;
115}
116
117template <class _InputIterator, class _OutputIterator>
118inline _LIBCPP_INLINE_VISIBILITY
119_OutputIterator
120partial_sum(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
121{
122    if (__first != __last)
123    {
124        typename iterator_traits<_InputIterator>::value_type __t(*__first);
125        *__result = __t;
126        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
127        {
128            __t = __t + *__first;
129            *__result = __t;
130        }
131    }
132    return __result;
133}
134
135template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
136inline _LIBCPP_INLINE_VISIBILITY
137_OutputIterator
138partial_sum(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
139              _BinaryOperation __binary_op)
140{
141    if (__first != __last)
142    {
143        typename iterator_traits<_InputIterator>::value_type __t(*__first);
144        *__result = __t;
145        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
146        {
147            __t = __binary_op(__t, *__first);
148            *__result = __t;
149        }
150    }
151    return __result;
152}
153
154template <class _InputIterator, class _OutputIterator>
155inline _LIBCPP_INLINE_VISIBILITY
156_OutputIterator
157adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
158{
159    if (__first != __last)
160    {
161        typename iterator_traits<_InputIterator>::value_type __t1(*__first);
162        *__result = __t1;
163        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
164        {
165            typename iterator_traits<_InputIterator>::value_type __t2(*__first);
166            *__result = __t2 - __t1;
167            __t1 = _VSTD::move(__t2);
168        }
169    }
170    return __result;
171}
172
173template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
174inline _LIBCPP_INLINE_VISIBILITY
175_OutputIterator
176adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
177                      _BinaryOperation __binary_op)
178{
179    if (__first != __last)
180    {
181        typename iterator_traits<_InputIterator>::value_type __t1(*__first);
182        *__result = __t1;
183        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
184        {
185            typename iterator_traits<_InputIterator>::value_type __t2(*__first);
186            *__result = __binary_op(__t2, __t1);
187            __t1 = _VSTD::move(__t2);
188        }
189    }
190    return __result;
191}
192
193template <class _ForwardIterator, class _Tp>
194inline _LIBCPP_INLINE_VISIBILITY
195void
196iota(_ForwardIterator __first, _ForwardIterator __last, _Tp __value_)
197{
198    for (; __first != __last; ++__first, (void) ++__value_)
199        *__first = __value_;
200}
201
202
203#if _LIBCPP_STD_VER > 14
204template <typename _Result, typename _Source, bool _IsSigned = is_signed<_Source>::value> struct __abs;
205
206template <typename _Result, typename _Source>
207struct __abs<_Result, _Source, true> {
208    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
209    _Result operator()(_Source __t) const noexcept
210    {
211    if (__t >= 0) return __t;
212    if (__t == numeric_limits<_Source>::min()) return -static_cast<_Result>(__t);
213    return -__t;
214    }
215};
216
217template <typename _Result, typename _Source>
218struct __abs<_Result, _Source, false> {
219    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
220    _Result operator()(_Source __t) const noexcept { return __t; }
221};
222
223
224template<class _Tp>
225_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
226_Tp __gcd(_Tp __m, _Tp __n)
227{
228    static_assert((!is_signed<_Tp>::value), "");
229    return __n == 0 ? __m : __gcd<_Tp>(__n, __m % __n);
230}
231
232
233template<class _Tp, class _Up>
234_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
235common_type_t<_Tp,_Up>
236gcd(_Tp __m, _Up __n)
237{
238    static_assert((is_integral<_Tp>::value && is_integral<_Up>::value), "Arguments to gcd must be integer types");
239    static_assert((!is_same<typename remove_cv<_Tp>::type, bool>::value), "First argument to gcd cannot be bool" );
240    static_assert((!is_same<typename remove_cv<_Up>::type, bool>::value), "Second argument to gcd cannot be bool" );
241    using _Rp = common_type_t<_Tp,_Up>;
242    using _Wp = make_unsigned_t<_Rp>;
243    return static_cast<_Rp>(__gcd(static_cast<_Wp>(__abs<_Rp, _Tp>()(__m)),
244                                  static_cast<_Wp>(__abs<_Rp, _Up>()(__n))));
245}
246
247template<class _Tp, class _Up>
248_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
249common_type_t<_Tp,_Up>
250lcm(_Tp __m, _Up __n)
251{
252    static_assert((is_integral<_Tp>::value && is_integral<_Up>::value), "Arguments to lcm must be integer types");
253    static_assert((!is_same<typename remove_cv<_Tp>::type, bool>::value), "First argument to lcm cannot be bool" );
254    static_assert((!is_same<typename remove_cv<_Up>::type, bool>::value), "Second argument to lcm cannot be bool" );
255    if (__m == 0 || __n == 0)
256        return 0;
257
258    using _Rp = common_type_t<_Tp,_Up>;
259    _Rp __val1 = __abs<_Rp, _Tp>()(__m) / gcd(__m, __n);
260    _Rp __val2 = __abs<_Rp, _Up>()(__n);
261    _LIBCPP_ASSERT((numeric_limits<_Rp>::max() / __val1 > __val2), "Overflow in lcm");
262    return __val1 * __val2;
263}
264
265#endif /* _LIBCPP_STD_VER > 14 */
266
267_LIBCPP_END_NAMESPACE_STD
268
269#endif  // _LIBCPP_NUMERIC
270