名前空間
変種
操作

std::random_shuffle, std::shuffle

提供: cppreference.com
< cpp‎ | algorithm

 
 
アルゴリズムライブラリ
機能します
Original:
Functions
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
シーケンス動作を非改変
Original:
Non-modifying sequence operations
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
シーケンス動作を変更する
Original:
Modifying sequence operations
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
操作を仕切る
Original:
Partitioning operations
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
(ソートされた範囲で)ソート操作
Original:
Sorting operations (on sorted ranges)
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
バイナリ検索操作(ソート範囲で)
Original:
Binary search operations (on sorted ranges)
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
(ソートされた範囲で)操作を設定します
Original:
Set operations (on sorted ranges)
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
ヒープ操作
Original:
Heap operations
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
最小値/最大値操作
Original:
Minimum/maximum operations
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
数値演算
Original:
Numeric operations
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Cライブラリ
Original:
C library
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
 
Defined in header <algorithm>
template< class RandomIt >
void random_shuffle( RandomIt first, RandomIt last );
(1)
template< class RandomIt, class RandomFunc >

void random_shuffle( RandomIt first, RandomIt last, RandomFunc& r );

template< class RandomIt, class RandomFunc >

void random_shuffle( RandomIt first, RandomIt last, RandomFunc&& r );
(2) (C + + 11時まで)



(C + + 11以来)
template< class RandomIt, class URNG >
void shuffle( RandomIt first, RandomIt last, URNG&& g );
(3) (C + + 11以来)
与えられた範囲内の要素[first, last)それらの要素の各々の可能な順列は、外観の等しい確率を持っていることなどを並べ替える.
Original:
Reorders the elements in the given range [first, last) such that each possible permutation of those elements has equal probability of appearance.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
1)
乱数発生器は実装定義であるが、関数std::randが用いられることが多い.
Original:
The random number generator is implementation-defined, but the function std::rand is often used.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
2)
乱数ジェネレータは関数オブジェクトrです.
Original:
The random number generator is the function object r.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
3)
乱数ジェネレータは関数オブジェクトgです.
Original:
The random number generator is the function object g.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

目次

[編集] パラメータ

first, last -
ランダムにシャッフルする要素の範囲
Original:
the range of elements to shuffle randomly
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
r -
iterator_traits<RandomIt>::difference_typeとして呼び出された場合、区間内r(n)[0〜コンバーチブル型、nのランダムに選択された値を返す関数オブジェクト)
Original:
function object returning a randomly chosen value of type convertible to iterator_traits<RandomIt>::difference_type in the interval [0,n) if invoked as r(n)
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
g -
間隔でタイプURNG::result_typeのランダムに選択された値を返す関数オブジェクト[g.min()、g.max()]g()(例えば<random>から一様乱数発生器のいずれか)として呼び出された場合
Original:
function object returning a randomly chosen value of type URNG::result_type in the interval [g.min(), g.max()] if invoked as g() (e.g. any of the uniform random number generators from <random>)
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
Type requirements
-
RandomIt must meet the requirements of ValueSwappable and RandomAccessIterator.
-
URNG must meet the requirements of UniformRandomNumberGenerator.

[編集] 値を返します

(なし)
Original:
(none)
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[編集] 複雑

firstlastとの間の距離の線形
Original:
linear in the distance between first and last
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

[編集] 可能な実装

First version
template<class RandomIt, class RandomFunc>
void random_shuffle(RandomIt first, RandomIt last, RandomFunc&& r)
{
    typename std::iterator_traits<RandomIt>::difference_type i, n;
    n = last - first;
    for (i = n-1; i > 0; --i) {
        using std::swap;
        swap(first[i], first[r(i+1)]);
    }
}
Second version
template<class RandomIt, class UniformRandomNumberGenerator>
void shuffle(RandomIt first, RandomIt last, 
             UniformRandomNumberGenerator&& g)
{
    typedef typename std::iterator_traits<RandomIt>::difference_type diff_t;
    typedef typename std::make_unsigned<diff_t>::type udiff_t;
    typedef typename std::uniform_int_distribution<udiff_t> distr_t;
    typedef typename distr_t::param_type param_t;
 
    distr_t D;
    diff_t n = last - first;
    for (diff_t i = n-1; i > 0; --i) {
        using std::swap;
        swap(first[i], first[D(g, param_t(0, i))]);
    }
}

[編集]

次のコードは、ランダムに整数1 .. 10を切り直す
Original:
The following code randomly shuffles the integers 1..10:
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.

#include <random>
#include <algorithm>
#include <iterator>
#include <iostream>
 
int main()
{
    std::vector<int> v = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
 
    std::random_device rd;
    std::mt19937 g(rd());
 
    std::shuffle(v.begin(), v.end(), g);
 
    copy(v.begin(), v.end(), std::ostream_iterator<int>(std::cout, " "));
    std::cout << "\n";
}


可能な出力:
Original:
Possible output:
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
8 6 10 4 2 3 7 1 9 5

[編集] も参照してください

generates the next greater lexicographic permutation of a range of elements
(関数テンプレート) [edit]
generates the next smaller lexicographic permutation of a range of elements
(関数テンプレート) [edit]