Jeff Thompson | ef2d5a4 | 2013-08-22 19:09:24 -0700 | [diff] [blame] | 1 | // Copyright (c) 2000 David Abrahams. |
| 2 | // Distributed under the Boost Software License, Version 1.0. |
| 3 | // (See accompanying file LICENSE_1_0.txt or copy at |
| 4 | // http://www.boost.org/LICENSE_1_0.txt) |
| 5 | // |
| 6 | // Copyright (c) 1994 |
| 7 | // Hewlett-Packard Company |
| 8 | // |
| 9 | // Permission to use, copy, modify, distribute and sell this software |
| 10 | // and its documentation for any purpose is hereby granted without fee, |
| 11 | // provided that the above copyright notice appear in all copies and |
| 12 | // that both that copyright notice and this permission notice appear |
| 13 | // in supporting documentation. Hewlett-Packard Company makes no |
| 14 | // representations about the suitability of this software for any |
| 15 | // purpose. It is provided "as is" without express or implied warranty. |
| 16 | // |
| 17 | // Copyright (c) 1996 |
| 18 | // Silicon Graphics Computer Systems, Inc. |
| 19 | // |
| 20 | // Permission to use, copy, modify, distribute and sell this software |
| 21 | // and its documentation for any purpose is hereby granted without fee, |
| 22 | // provided that the above copyright notice appear in all copies and |
| 23 | // that both that copyright notice and this permission notice appear |
| 24 | // in supporting documentation. Silicon Graphics makes no |
| 25 | // representations about the suitability of this software for any |
| 26 | // purpose. It is provided "as is" without express or implied warranty. |
| 27 | // |
| 28 | #ifndef BINARY_SEARCH_DWA_122600_H_ |
| 29 | # define BINARY_SEARCH_DWA_122600_H_ |
| 30 | |
| 31 | # include <ndnboost/detail/iterator.hpp> |
| 32 | # include <utility> |
| 33 | |
| 34 | namespace ndnboost { namespace detail { |
| 35 | |
| 36 | template <class ForwardIter, class Tp> |
| 37 | ForwardIter lower_bound(ForwardIter first, ForwardIter last, |
| 38 | const Tp& val) |
| 39 | { |
| 40 | typedef detail::iterator_traits<ForwardIter> traits; |
| 41 | |
| 42 | typename traits::difference_type len = ndnboost::detail::distance(first, last); |
| 43 | typename traits::difference_type half; |
| 44 | ForwardIter middle; |
| 45 | |
| 46 | while (len > 0) { |
| 47 | half = len >> 1; |
| 48 | middle = first; |
| 49 | std::advance(middle, half); |
| 50 | if (*middle < val) { |
| 51 | first = middle; |
| 52 | ++first; |
| 53 | len = len - half - 1; |
| 54 | } |
| 55 | else |
| 56 | len = half; |
| 57 | } |
| 58 | return first; |
| 59 | } |
| 60 | |
| 61 | template <class ForwardIter, class Tp, class Compare> |
| 62 | ForwardIter lower_bound(ForwardIter first, ForwardIter last, |
| 63 | const Tp& val, Compare comp) |
| 64 | { |
| 65 | typedef detail::iterator_traits<ForwardIter> traits; |
| 66 | |
| 67 | typename traits::difference_type len = ndnboost::detail::distance(first, last); |
| 68 | typename traits::difference_type half; |
| 69 | ForwardIter middle; |
| 70 | |
| 71 | while (len > 0) { |
| 72 | half = len >> 1; |
| 73 | middle = first; |
| 74 | std::advance(middle, half); |
| 75 | if (comp(*middle, val)) { |
| 76 | first = middle; |
| 77 | ++first; |
| 78 | len = len - half - 1; |
| 79 | } |
| 80 | else |
| 81 | len = half; |
| 82 | } |
| 83 | return first; |
| 84 | } |
| 85 | |
| 86 | template <class ForwardIter, class Tp> |
| 87 | ForwardIter upper_bound(ForwardIter first, ForwardIter last, |
| 88 | const Tp& val) |
| 89 | { |
| 90 | typedef detail::iterator_traits<ForwardIter> traits; |
| 91 | |
| 92 | typename traits::difference_type len = ndnboost::detail::distance(first, last); |
| 93 | typename traits::difference_type half; |
| 94 | ForwardIter middle; |
| 95 | |
| 96 | while (len > 0) { |
| 97 | half = len >> 1; |
| 98 | middle = first; |
| 99 | std::advance(middle, half); |
| 100 | if (val < *middle) |
| 101 | len = half; |
| 102 | else { |
| 103 | first = middle; |
| 104 | ++first; |
| 105 | len = len - half - 1; |
| 106 | } |
| 107 | } |
| 108 | return first; |
| 109 | } |
| 110 | |
| 111 | template <class ForwardIter, class Tp, class Compare> |
| 112 | ForwardIter upper_bound(ForwardIter first, ForwardIter last, |
| 113 | const Tp& val, Compare comp) |
| 114 | { |
| 115 | typedef detail::iterator_traits<ForwardIter> traits; |
| 116 | |
| 117 | typename traits::difference_type len = ndnboost::detail::distance(first, last); |
| 118 | typename traits::difference_type half; |
| 119 | ForwardIter middle; |
| 120 | |
| 121 | while (len > 0) { |
| 122 | half = len >> 1; |
| 123 | middle = first; |
| 124 | std::advance(middle, half); |
| 125 | if (comp(val, *middle)) |
| 126 | len = half; |
| 127 | else { |
| 128 | first = middle; |
| 129 | ++first; |
| 130 | len = len - half - 1; |
| 131 | } |
| 132 | } |
| 133 | return first; |
| 134 | } |
| 135 | |
| 136 | template <class ForwardIter, class Tp> |
| 137 | std::pair<ForwardIter, ForwardIter> |
| 138 | equal_range(ForwardIter first, ForwardIter last, const Tp& val) |
| 139 | { |
| 140 | typedef detail::iterator_traits<ForwardIter> traits; |
| 141 | |
| 142 | typename traits::difference_type len = ndnboost::detail::distance(first, last); |
| 143 | typename traits::difference_type half; |
| 144 | ForwardIter middle, left, right; |
| 145 | |
| 146 | while (len > 0) { |
| 147 | half = len >> 1; |
| 148 | middle = first; |
| 149 | std::advance(middle, half); |
| 150 | if (*middle < val) { |
| 151 | first = middle; |
| 152 | ++first; |
| 153 | len = len - half - 1; |
| 154 | } |
| 155 | else if (val < *middle) |
| 156 | len = half; |
| 157 | else { |
| 158 | left = ndnboost::detail::lower_bound(first, middle, val); |
| 159 | std::advance(first, len); |
| 160 | right = ndnboost::detail::upper_bound(++middle, first, val); |
| 161 | return std::pair<ForwardIter, ForwardIter>(left, right); |
| 162 | } |
| 163 | } |
| 164 | return std::pair<ForwardIter, ForwardIter>(first, first); |
| 165 | } |
| 166 | |
| 167 | template <class ForwardIter, class Tp, class Compare> |
| 168 | std::pair<ForwardIter, ForwardIter> |
| 169 | equal_range(ForwardIter first, ForwardIter last, const Tp& val, |
| 170 | Compare comp) |
| 171 | { |
| 172 | typedef detail::iterator_traits<ForwardIter> traits; |
| 173 | |
| 174 | typename traits::difference_type len = ndnboost::detail::distance(first, last); |
| 175 | typename traits::difference_type half; |
| 176 | ForwardIter middle, left, right; |
| 177 | |
| 178 | while (len > 0) { |
| 179 | half = len >> 1; |
| 180 | middle = first; |
| 181 | std::advance(middle, half); |
| 182 | if (comp(*middle, val)) { |
| 183 | first = middle; |
| 184 | ++first; |
| 185 | len = len - half - 1; |
| 186 | } |
| 187 | else if (comp(val, *middle)) |
| 188 | len = half; |
| 189 | else { |
| 190 | left = ndnboost::detail::lower_bound(first, middle, val, comp); |
| 191 | std::advance(first, len); |
| 192 | right = ndnboost::detail::upper_bound(++middle, first, val, comp); |
| 193 | return std::pair<ForwardIter, ForwardIter>(left, right); |
| 194 | } |
| 195 | } |
| 196 | return std::pair<ForwardIter, ForwardIter>(first, first); |
| 197 | } |
| 198 | |
| 199 | template <class ForwardIter, class Tp> |
| 200 | bool binary_search(ForwardIter first, ForwardIter last, |
| 201 | const Tp& val) { |
| 202 | ForwardIter i = ndnboost::detail::lower_bound(first, last, val); |
| 203 | return i != last && !(val < *i); |
| 204 | } |
| 205 | |
| 206 | template <class ForwardIter, class Tp, class Compare> |
| 207 | bool binary_search(ForwardIter first, ForwardIter last, |
| 208 | const Tp& val, |
| 209 | Compare comp) { |
| 210 | ForwardIter i = ndnboost::detail::lower_bound(first, last, val, comp); |
| 211 | return i != last && !comp(val, *i); |
| 212 | } |
| 213 | |
| 214 | }} // namespace ndnboost::detail |
| 215 | |
| 216 | #endif // BINARY_SEARCH_DWA_122600_H_ |