std::unique_copy
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Defined in header <algorithm>
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template< class InputIt, class OutputIt > ForwardIt unique_copy( InputIt first, InputIt last, |
(1) | |
template< class InputIt, class OutputIt, class BinaryPredicate > ForwardIt unique_copy( InputIt first, InputIt last, |
(2) | |
Kopiert die Elemente aus dem Bereich
[first, last)
, in einen anderen Bereich beginnend bei d_first
derart, dass es keine aufeinanderfolgenden gleichen Elemente. Nur das erste Element einer jeden Gruppe von gleichen Elementen kopiert wird. Die erste Version verwendet operator==
um die Elemente zu vergleichen, verwendet die zweite Version des gegebenen binären Prädikats p
.Original:
Copies the elements from the range
[first, last)
, to another range beginning at d_first
in such a way that there are no consecutive equal elements. Only the first element of each group of equal elements is copied. The first version uses operator==
to compare the elements, the second version uses the given binary predicate p
.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.
Inhaltsverzeichnis |
[Bearbeiten] Parameter
first, last | - | der Bereich der Elemente zu verarbeiten
Original: the range of elements to process The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. | |||||||||
d_first | - | der Beginn des Zielbereichs
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. | |||||||||
p | - | binary predicate which returns true if the elements should be treated as equal. The signature of the predicate function should be equivalent to the following:
The signature does not need to have const &, but the function must not modify the objects passed to it. | |||||||||
Type requirements | |||||||||||
-InputIt must meet the requirements of InputIterator .
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-OutputIt must meet the requirements of OutputIterator .
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-The type of dereferenced InputIt must meet the requirements of CopyAssignable .
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-The type of dereferenced InputIt must meet the requirements of CopyConstructible . if neither InputIt nor OutputIt satisfies ForwardIterator
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[Bearbeiten] Rückgabewert
Output Iterator auf das Element nach dem letzten schriftlichen Element
Original:
Output iterator to the element past the last written element
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[Bearbeiten] Mögliche Implementierung
First version |
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template<class ForwardIt, class OutputIt> ForwardIt unique_copy(ForwardIt first, ForwardIt last, OutputIt d_first) { if (first == last) return d_first; *d_first = *first; while (++first != last) { if (!(*d_first == *first)) { *(++d_first) = *first; } } return ++d_first; } |
Second version |
template<class ForwardIt, class OutputIt, class BinaryPredicate> ForwardIt unique_copy(ForwardIt first, ForwardIt last, OutputIt d_first, BinaryPredicate p) { if (first == last) return d_first; *d_first = *first; while (++first != last) { if (!p(*result, *first)) { *(++d_first) = *first; } } return ++d_first; } |
[Bearbeiten] Beispiel
Das folgende Programm trimmt alle mehrere aufeinander folgende Leerzeichen in einer const string und gibt das Ergebnis
Original:
The following program trims all multiple consecutive spaces in a const string and prints the result
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#include <string> #include <iostream> #include <algorithm> #include <iterator> int main() { std::string s1 = "The string with many spaces!"; std::cout << "before: " << s1 << '\n'; std::string s2; std::unique_copy(s1.begin(), s1.end(), std::back_inserter(s2), [](char c1, char c2){ return c1 == ' ' && c2 == ' '; }); std::cout << "after: " << s2 << '\n'; }
Output:
before: The string with many spaces! after: The string with many spaces!
[Bearbeiten] Komplexität
linear im Abstand
first
und last
Original:
linear in the distance between
first
and last
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[Bearbeiten] Siehe auch
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) | |
removes consecutive duplicate elements in a range (Funktions-Template) |