std::min_element – cppreference.com

std::min_element

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C++
 
Algorithm Bibliothek
Funktionen
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Functions
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Nicht-modifizierende Sequenz Operationen
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Non-modifying sequence operations
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Modifizierende Sequenz Operationen
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Modifying sequence operations
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Partitionierungsoperationen
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Partitioning operations
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Sortierung Operationen (auf sortierten Bereiche)
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Sorting operations (on sorted ranges)
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Binary Suchaktionen (auf sortierten Bereiche)
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Binary search operations (on sorted ranges)
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Set-Operationen (auf sortierten Bereiche)
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Set operations (on sorted ranges)
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Heap-Operationen
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Heap operations
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Minimum / Maximum Operationen
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Minimum/maximum operations
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Numerische Operationen
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Numeric operations
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C-Bibliothek
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C library
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<tbody> </tbody>
definiert in Header <algorithm>
template< class ForwardIt > ForwardIt min_element( ForwardIt first, ForwardIt last );
 (1)
template< class ForwardIt, class Compare > ForwardIt min_element( ForwardIt first, ForwardIt last, Compare comp );
 (2)
Findet das kleinste Element im Bereich [first, last). Die erste Version verwendet operator< um die Werte zu vergleichen, verwendet die zweite Version des gegebenen Vergleichsfunktion comp .
Original:
Finds the smallest element in the range [first, last). The first version uses operator< to compare the values, the second version uses the given comparison function comp.
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Parameter

first, last -
Vorwärts Iteratoren definieren den Bereich zu prüfen
Original:
forward iterators defining the range to examine
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cmp - comparison function which returns ​true if if *a is less than *b.

The signature of the comparison function should be equivalent to the following:

bool cmp(const Type1 &a, const Type2 &b);

The signature does not need to have const &, but the function must not modify the objects passed to it.
The types Type1 and Type2 must be such that an object of type ForwardIt can be dereferenced and then implicitly converted to both of them. ​

Type requirements
-
ForwardIt must meet the requirements of ForwardIterator.

Rückgabewert

Iterator zum kleinsten Element in dem Bereich [first, last). Wenn mehrere Elemente im Bereich entspricht der kleinsten Element vorhanden sind, gibt den Iterator auf das erste Element. Versandkosten last wenn der Bereich leer ist .
Original:
Iterator to the smallest element in the range [first, last). If several elements in the range are equivalent to the smallest element, returns the iterator to the first such element. Returns last if the range is empty.
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Komplexität

Genau max(N-1,0) Vergleiche, wo N = std::distance(first, last) .
Original:
Exactly max(N-1,0) comparisons, where N = std::distance(first, last).
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Mögliche Implementierung

First version 
template<class ForwardIt>
ForwardIt min_element(ForwardIt first, ForwardIt last)
{
    if (first == last) return last;

    ForwardIt smallest = first;
    ++first;
    for (; first != last; ++first) {
        if (*first < *smallest) {
            smallest = first;
        }
    }
    return smallest;
}
Second version 
template<class ForwardIt, class Compare>
ForwardIt min_element(ForwardIt first, ForwardIt last, 
                            Compare comp)
{
    if (first == last) return last;
    
    ForwardIt smallest = first;
    ++first;
    for (; first != last; ++first) {
        if (comp(*first, *smallest)) {
            smallest = first;
        }
    }
    return smallest;
}

Beispiel

#include <algorithm>
#include <iostream>
#include <vector>
 
int main()
{
    std::vector<int> v{3, 1, 4, 1, 5, 9};
 
    std::vector<int>::iterator result = std::min_element(v.begin(), v.end());
    std::cout << "min element at: " << std::distance(v.begin(), result);
}

Output: 

min element at: 1

Siehe auch