std::find, std::find_if, std::find_if_not

 

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Funktionen Original: Functions The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
Nicht-modifizierende Sequenz Operationen 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.
all_of any_of none_of (C++11) (C++11) (C++11) for_each count count_if mismatch equal	find find_if find_if_not (C++11) find_end find_first_of adjacent_find search search_n
Modifizierende Sequenz Operationen 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.
copy copy_if (C++11) copy_n (C++11) copy_backward move (C++11) move_backward (C++11) fill fill_n transform generate generate_n remove remove_if remove_copy remove_copy_if	replace replace_if replace_copy replace_copy_if swap swap_ranges iter_swap reverse reverse_copy rotate rotate_copy random_shuffle shuffle   (C++11) unique unique_copy
Partitionierungsoperationen 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.
is_partitioned (C++11) partition partition_copy (C++11)	stable_partition partition_point (C++11)
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is_sorted (C++11) is_sorted_until (C++11) sort	partial_sort partial_sort_copy stable_sort nth_element
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lower_bound upper_bound	binary_search equal_range
Set-Operationen (auf sortierten Bereiche) 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.
merge inplace_merge includes	set_difference set_intersection set_symmetric_difference set_union
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is_heap is_heap_until (C++11) make_heap	push_heap pop_heap sort_heap
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max max_element min min_element minmax (C++11) minmax_element (C++11)	lexicographical_compare is_permutation (C++11) next_permutation prev_permutation
Numerische Operationen 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.
iota (C++11) accumulate inner_product	adjacent_difference partial_sum
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qsort	bsearch

 

Defined in header <algorithm>
template< class InputIt, class T > InputIt find( InputIt first, InputIt last, const T& value );	(1)
template< class InputIt, class UnaryPredicate > InputIt find_if( InputIt first, InputIt last,                  UnaryPredicate p );	(2)
template< class InputIt, class UnaryPredicate > InputIt find_if_not( InputIt first, InputIt last,                      UnaryPredicate q );	(3)	(seit C++11)

Diese Funktionen finden Sie das erste Element im Bereich [first, last), die bestimmte Kriterien erfüllt:

Original:

These functions find the first element in the range [first, last) that satisfies specific criteria:

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Ein. find Suche nach einem Element gleich value

Original:

1. find searches for an element equal to value

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2. find_if sucht nach einem Element, für das Prädikat p kehrt true

Original:

2. find_if searches for an element for which predicate p returns true

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3. find_if_not sucht Element, für das Prädikat q kehrt false

Original:

3. find_if_not searches for element for which predicate q returns false

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Parameter

first, last	-	das Spektrum der Elemente zu untersuchen Original: the range of elements to examine The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
value	-	Wert auf die Elemente zu vergleichen Original: value to compare the elements to The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
p	-	unary predicate which returns ​true für das gewünschte Element Original: for the required element 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 predicate function should be equivalent to the following: bool pred(const Type &a); The signature does not need to have const &, but the function must not modify the objects passed to it. The type Type must be such that an object of type InputIt can be dereferenced and then implicitly converted to Type. ​
q	-	unary predicate which returns ​false für das gewünschte Element Original: for the required element 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 predicate function should be equivalent to the following: bool pred(const Type &a); The signature does not need to have const &, but the function must not modify the objects passed to it. The type Type must be such that an object of type InputIt can be dereferenced and then implicitly converted to Type. ​
Type requirements
- InputIt must meet the requirements of InputIterator.

Rückgabewert

Iterator auf das erste Element, die der Bedingung oder last wenn ein solches Element gefunden wird .

Original:

Iterator to the first element satisfying the condition or last if no such element is found.

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Komplexität

An den meisten last - first Anwendungen des Prädikats

Original:

At most last - first applications of the predicate

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Mögliche Implementierung

First version
template<class InputIt, class T> InputIt find(InputIt first, InputIt last, const T& value) { for (; first != last; ++first) { if (*first == value) { return first; } } return last; }
Second version
template<class InputIt, class UnaryPredicate> InputIt find_if(InputIt first, InputIt last, UnaryPredicate p) { for (; first != last; ++first) { if (p(*first)) { return first; } } return last; }
Third version
template<class InputIt, class UnaryPredicate> InputIt find_if_not(InputIt first, InputIt last, UnaryPredicate q) { for (; first != last; ++first) { if (!q(*first)) { return first; } } return last; }

Wenn Sie keinen C + +11, ein Äquivalent zu std::find_if_not ist std::find_if mit dem negierten Prädikat verwenden .

Original:

If you do not have C++11, an equivalent to std::find_if_not is to use std::find_if with the negated predicate.

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template<class InputIt, class UnaryPredicate> InputIt find_if_not(InputIt first, InputIt last, UnaryPredicate q) { return std::find_if(first, last, std::not1(q)); }

Beispiel

Im folgenden Beispiel wird eine ganze Zahl in einem Vektor von ganzen Zahlen .

Original:

The following example finds an integer in a vector of integers.

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#include <iostream>
#include <algorithm>
#include <vector>
 
int main()
{
    int n1 = 3;
    int n2 = 5;
 
    std::vector<int> v{0, 1, 2, 3, 4};
 
    auto result1 = std::find(v.begin(), v.end(), n1);
    auto result2 = std::find(v.begin(), v.end(), n2);
 
    if (result1 != v.end()) {
        std::cout << "v contains: " << n1 << '\n';
    } else {
        std::cout << "v does not contain: " << n1 << '\n';
    }
 
    if (result2 != v.end()) {
        std::cout << "v contains: " << n2 << '\n';
    } else {
        std::cout << "v does not contain: " << n2 << '\n';
    }
}

Output:

v contains: 3
v does not contain: 5

Siehe auch

adjacent_find	findet zwei identischen (oder eine andere Beziehung) Elemente einander benachbart Original: finds two identical (or some other relationship) items adjacent to each other The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Funktions-Template)
find_end	findet die letzte Sequenz von Elementen in einem bestimmten Bereich Original: finds the last sequence of elements in a certain range The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Funktions-Template)
find_first_of	searches for any one of a set of elements (Funktions-Template)
mismatch	findet die erste Position, wo zwei Bereiche unterscheiden Original: finds the first position where two ranges differ The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (Funktions-Template)
search	searches for a range of elements (Funktions-Template)