std::partial_sum
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| Defined in header <numeric>
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| template< class InputIt, class OutputIt > OutputIt partial_sum( InputIt first, InputIt last, OutputIt d_first ); |
(1) | |
| template< class InputIt, class OutputIt, class BinaryOperation > OutputIt partial_sum( InputIt first, InputIt last, OutputIt d_first, |
(2) | |
[first, last)の部分範囲内の要素の部分和を計算し、d_firstで範囲の先頭に書き込みます。最初のバージョンは、要素を総括するoperator+使用し、2番目のバージョンは、指定されたバイナリop機能を使用しています.[first, last) and writes them to the range beginning at d_first. The first version uses operator+ to sum up the elements, the second version uses the given binary function op.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.
*(d_first) = *first; *(d_first+1) = *first + *(first+1); *(d_first+2) = *first + *(first+1) + *(first+2); *(d_first+3) = *first + *(first+1) + *(first+2) + *(first+3); ...
目次 |
[編集] パラメータ
| first, last | - | 和への要素の範囲
Original: the range of elements to sum The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. | |||||||||
| d_first | - | 目的の範囲の始まり
Original: the beginning of the destination range The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. | |||||||||
| op | - | binary operation function object that will be applied. The signature of the function should be equivalent to the following:
The signature does not need to have const &. | |||||||||
| Type requirements | |||||||||||
-InputIt must meet the requirements of InputIterator.
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-OutputIt must meet the requirements of OutputIterator.
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[編集] 値を返します
You can help to correct and verify the translation. Click here for instructions.
[編集] 複雑
(last - first) - 1アプリケーション(last - first) - 1 applications of the binary operationYou can help to correct and verify the translation. Click here for instructions.
[編集] 可能な実装
| First version |
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template<class InputIt, class OutputIt> OutputIt partial_sum(InputIt first, InputIt last, OutputIt d_first) { return std::partial_sum(first, last, d_first, std::plus<InputIt, InputIt>()); } |
| Second version |
template<class InputIt, class OutputIt, class BinaryOperator> OutputIt partial_sum(InputIt first, InputIt last, OutputIt d_first, BinaryOperation op) { if (first == last) return d_first; typename std::iterator_traits<InputIt>::value_type sum = *first; *d_first = sum; while (++first != last) { sum = op(sum, *first); *++d_first = sum; } return ++d_first; } |
[編集] 例
#include <numeric> #include <vector> #include <iostream> #include <iterator> #include <functional> int main() { std::vector<int> v = {2,2,2,2,2,2,2,2,2,2}; std::cout << "The first 10 even numbers are: "; std::partial_sum(v.begin(), v.end(), std::ostream_iterator<int>(std::cout, " ")); std::cout << '\n'; std::partial_sum(v.begin(), v.end(), v.begin(), std::multiplies<int>()); std::cout << "The first 10 powers of 2 are: "; for(auto n: v) { std::cout << n << " "; } std::cout << '\n'; }
Output:
The first 10 even numbers are: 2 4 6 8 10 12 14 16 18 20 The first 10 powers of 2 are: 2 4 8 16 32 64 128 256 512 1024
[編集] も参照してください
| 範囲内の隣接する要素間の差を計算します Original: computes the differences between adjacent elements 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) | |
| 要素の範囲をまとめている Original: sums up a range of elements 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) | |