std::minmax_element
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Defined in header <algorithm>
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template< class ForwardIt > std::pair<ForwardIt,ForwardIt> |
(1) | |
template< class ForwardIt, class Compare > std::pair<ForwardIt,ForwardIt> |
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レンジ
[first, last)
で最大と最小の要素を検索します。最初のバージョンは、値を比較するoperator<使用して、2番目のバージョンは、指定された比較関数comp
を使用しています.Original:
Finds the greatest and the smallest element in the range
[first, last)
. The first version uses operator< to compare the values, the second version uses the given comparison function comp
.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
目次 |
[編集] パラメータ
first, last | - | 検討する範囲を定義前方反復子
Original: forward iterators defining the range to examine The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
cmp | - | comparison function which returns true if if *a is less than *b . The signature of the comparison function should be equivalent to the following: bool cmp(const Type1 &a, const Type2 &b); The signature does not need to have const &, but the function must not modify the objects passed to it. |
Type requirements | ||
-ForwardIt must meet the requirements of ForwardIterator .
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[編集] 値を返します
最初の要素と第二として最大の要素を指すイテレータとして最小の要素を指すイテレータからなるペア。戻りstd::make_pair(first, first)範囲が空の場合。いくつかの要素が最小の要素と同等である場合は、まずそのような要素を指すイテレータを返す。いくつかの要素が最大の要素と同等である場合は、最後にそのような要素を指すイテレータを返す.
Original:
a pair consisting of an iterator to the smallest element as the first element and an iterator to the greatest element as the second. Returns std::make_pair(first, first) if the range is empty. If several elements are equivalent to the smallest element, the iterator to the first such element is returned. If several elements are equivalent to the largest element, the iterator to the last such element is returned.
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[編集] 複雑
述部の中で最もmax(floor(3/2(N−1)), 0)アプリケーションで、どこN = std::distance(first, last).
Original:
At most max(floor(3/2(N−1)), 0) applications of the predicate, where N = std::distance(first, last).
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[編集] 可能な実装
First version |
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template<class ForwardIt> std::pair<ForwardIt, ForwardIt> minmax_element(ForwardIt first, ForwardIt last) { typedef typename std::iterator_traits<ForwardIt>::value_type value_t; return std::minmax_element(first, last, std::less<value_t>()); } |
Second version |
template<class ForwardIt, class Compare> std::pair<ForwardIt, ForwardIt> minmax_element(ForwardIt first, ForwardIt last, Compare comp) { std::pair<ForwardIt, ForwardIt> result(first, first); if (first == last) return result; if (++first == last) return result; if (comp(*first, *result.first)) { result.second = result.first; result.first = first; } else { result.second = first; } while (++first != last) { ForwardIt i = first; if (++first == last) { if (comp(*i, *result.first)) result.first = i; else if (!(comp(*i, *result.second))) result.second = i; break; } else { if (comp(*first, *i)) { if (comp(*first, *result.first)) result.first = first; if (!(comp(*i, *result.second))) result.second = i; } else { if (comp(*i, *result.first)) result.first = i; if (!(comp(*first, *result.second))) result.second = first; } } } return result; } |
[編集] 例
#include <algorithm> #include <iostream> #include <vector> int main() { std::vector<int> v = { 3, 9, 1, 4, 2, 5, 9 }; auto result = std::minmax_element(v.begin(), v.end()); std::cout << "min element at: " << (result.first - v.begin()) << '\n'; std::cout << "max element at: " << (result.second - v.begin()) << '\n'; }
Output:
min element at: 2 max element at: 6
[編集] も参照してください
範囲内の最小の要素を返します Original: returns the smallest element in a range The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (関数テンプレート) | |
範囲内の最大の要素を返します Original: returns the largest element in a range The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (関数テンプレート) |