std::make_heap – cppreference.com

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definiert in Header `<algorithm>`

`template< class RandomIt > void make_heap( RandomIt first, RandomIt last );`	(1)

`template< class RandomIt, class Compare > void make_heap( RandomIt first, RandomIt last, Compare comp );`	(2)

Erzeugt ein Haufen im Bereich [first, last). Die erste Version der Funktion verwendet operator<, um die Elemente zu vergleichen, verwendet die zweite der angegebenen Vergleichsfunktion comp .

Original:

Constructs a heap in the range [first, last). The first version of the function uses operator< to compare the elements, the second uses the given comparison function comp.

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Parameter

first, last	-	das Spektrum der Elemente, um die Haufen aus zu machen Original: the range of elements to make the heap from The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions.
comp	-	comparison function which returns `true` if the first argument is less than the second. 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 `RandomIt` can be dereferenced and then implicitly converted to both of them.
Type requirements
-`RandomIt` must meet the requirements of `RandomAccessIterator`.
-The type of dereferenced `RandomIt` must meet the requirements of `MoveAssignable` and `MoveConstructible`.

Rückgabewert

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Original:

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Komplexität

An den meisten 3*std::distance(first, last) Vergleiche .

Original:

At most 3*std::distance(first, last) comparisons.

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Notes

A Haufen ist ein Bereich von Elementen [f,l) das hat die folgenden Eigenschaften:

Original:

A heap is a range of elements [f,l) that has the following properties:

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*f ist das größte Element in dem Bereich
Original:
*f is the largest element in the range
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ein neues Element hinzugefügt mit std::push_heap() werden
Original:
a new element can be added using std::push_heap()
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das erste Element kann mit Hilfe std::pop_heap() werden
Original:
the first element can be removed using std::pop_heap()
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Die tatsächliche Anordnung der Elemente ist die Umsetzung definiert .

Original:

The actual arrangement of the elements is implementation defined.

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Beispiel

#include <iostream>
#include <algorithm>

int main()
{
    std::vector<int> v { 3, 1, 4, 1, 5, 9 };

    std::cout << "initially, v: ";
    for (auto i : v) std::cout << i << ' ';
    std::cout << '\n';

    std::make_heap(v.begin(), v.end());

    std::cout << "after make_heap, v: ";
    for (auto i : v) std::cout << i << ' ';
    std::cout << '\n';

    std::pop_heap(v.begin(), v.end());
    auto largest = v.back();
    v.pop_back();
    std::cout << "largest element: " << largest << '\n';

    std::cout << "after removing the largest element, v: ";
    for (auto i : v) std::cout << i << ' ';
    std::cout << '\n';
}

Output:

initially, v: 3 1 4 1 5 9 
after make_heap, v: 9 5 4 1 1 3 
largest element: 9
after removing the largest element, v: 5 3 4 1 1

Siehe auch


	verwandelt einen Heap in eine sortierte Auswahl an Elementen Original: turns a heap into a sorted 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. (Funktions-Template) [edit]