std::inner_product
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Defined in header <numeric> | ||
template<class InputIt1, class InputIt2, class T > T inner_product( InputIt1 first1, InputIt1 last1, | (1) | |
template< class InputIt1, | (2) | |
[first1, last1)とfirst2で別の範囲の始まりの内積（全商品の数すなわち和）を計算する。最初のバージョンは、製品を総括する要素のペアとoperator*の積を計算しoperator+使用して、2番目のバージョンは、それぞれとop2これらのタスクにop1を使用しています.[first1, last1) and another range beginning at first2. The first version uses operator* to compute product of the element pairs and operator+ to sum up the products, the second version uses op2 and op1 for these tasks respectively.You can help to correct and verify the translation. Click here for instructions.
目次 |
[編集]パラメータ
| first1, last1 | - | 最初の要素の範囲 Original: the first 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. |
| first2 | - | 要素の第2の範囲の始まり Original: the beginning of the second 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. |
| value | - | 積の和の初期値 Original: initial value of the sum of the products The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| op1 | - | binary operation function object that will be applied. この関数は、OP2によって返される値とアキュムレータの現在の値を取得し、アキュムレータに格納する新しい値を生成します. Original: This function takes a value returned by op2 and the current value of the accumulator and produces a new value to be stored in the accumulator. The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. The signature of the function should be equivalent to the following: Ret fun(const Type1 &a, const Type2 &b); The signature does not need to have const&. |
| op2 | - | binary operation function object that will be applied. この関数は、各範囲から1つの値をとり、新しい値を生成します. Original: This function takes one value from each range and produces a new value. The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. The signature of the function should be equivalent to the following: Ret fun(const Type1 &a, const Type2 &b); The signature does not need to have const&. |
| 型の要件 | ||
-InputIt1, InputIt2 は InputIteratorの要求を満足しなければなりません。 | ||
-T は CopyAssignable and CopyConstructible。 | ||
[編集]値を返します
You can help to correct and verify the translation. Click here for instructions.
[編集]可能な実装
| First version |
|---|
template<class InputIt1, class InputIt2, class T> T inner_product(InputIt1 first1, InputIt1 last1, InputIt2 first2, T value){while(first1 != last1){ value = value +*first1 **first2;++first1;++first2;}return value;} |
| Second version |
template<class InputIt1, class InputIt2, class T, class BinaryOperation1, class BinaryOperation2> T inner_product(InputIt1 first1, InputIt1 last1, InputIt2 first2, T value, BinaryOperation1 op1 BinaryOperation2 op2){while(first1 != last1){ value = op1(value, op2(*first1, *first2));++first1;++first2;}return value;} |
[編集]例
#include <numeric>#include <iostream>#include <vector>#include <functional>int main(){std::vector<int> a{0, 1, 2, 3, 4};std::vector<int> b{5, 4, 2, 3, 1}; int r1 = std::inner_product(a.begin(), a.end(), b.begin(), 0);std::cout<<"Inner product of a and b: "<< r1 <<'\n'; int r2 = std::inner_product(a.begin(), a.end(), b.begin(), 0, std::plus<int>(), std::equal_to<int>());std::cout<<"Number of pairwise matches between a and b: "<< r2 <<'\n';}
出力:
Inner product of a and b: 21 Number of pairwise matches between a and b: 2
[編集]参照
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) | |
要素の範囲の部分和を計算します Original: computes the partial sum of 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) | |
