std::merge
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Defined in header <algorithm> | ||
template<class InputIt1, class InputIt2, class OutputIt > OutputIt merge( InputIt1 first1, InputIt1 last1, | (1) | |
template<class InputIt1, class InputIt2, class OutputIt, class Compare> OutputIt merge( InputIt1 first1, InputIt1 last1, | (2) | |
[first1, last1)
e [first2, last2)
in un unico campo di inizio smistati d_first
. La prima versione utilizza operator< di confrontare gli elementi, la seconda versione utilizza la data comp
funzione di confronto. L'ordine relativo degli elementi equivalenti è conservato.[first1, last1)
and [first2, last2)
into one sorted range beginning at d_first
. The first version uses operator< to compare the elements, the second version uses the given comparison function comp
. The relative order of equivalent elements is preserved.You can help to correct and verify the translation. Click here for instructions.
Indice |
[modifica]Parametri
first1, last1 | - | la prima gamma di elementi da unire Original: the first range of elements to merge The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
first2, last2 | - | il secondo intervallo di elementi da unire Original: the second range of elements to merge The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
d_first | - | l'inizio del campo di destinazione 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. |
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. |
Type requirements | ||
-InputIt1 must meet the requirements of InputIterator . | ||
-InputIt2 must meet the requirements of InputIterator . | ||
-OutputIt must meet the requirements of OutputIterator . |
[modifica]Valore di ritorno
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[modifica]Complessità
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[modifica]Possibile implementazione
First version |
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template<class InputIt1, class InputIt2, class OutputIt> OutputIt merge(InputIt1 first1, InputIt1 last1, InputIt2 first2, InputIt2 last2, OutputIt d_first){for(; first1 != last1;++d_first){if(first2 == last2){returnstd::copy(first1, last1, d_first);}if(*first2 <*first1){*d_first =*first2;++first2;}else{*d_first =*first1;++first1;}}returnstd::copy(first2, last2, d_first);} |
Second version |
template<class InputIt1, class InputIt2, class OutputIt, class Compare> OutputIt merge(InputIt1 first1, InputIt1 last1, InputIt2 first2, InputIt2 last2, OutputIt d_first, Compare comp){for(; first1 != last1;++d_first){if(first2 == last2){returnstd::copy(first1, last1, d_first);}if(comp(*first2, *first1)){*d_first =*first2;++first2;}else{*d_first =*first1;++first1;}}returnstd::copy(first2, last2, d_first);} |
[modifica]Esempio
#include <iostream>#include <iterator>#include <cstdlib>#include <algorithm>#include <vector> int main(){conststd::size_t items =10; std::vector<int> v1, v2, dst; // fill the vectorsfor(std::size_t idx =0; idx < items;++idx){ v1.push_back(std::rand()%items); v2.push_back(std::rand()%items);} // sortstd::sort(v1.begin(), v1.end());std::sort(v2.begin(), v2.end()); // output v1std::cout<<"v1 : ";std::copy(v1.begin(), v1.end(), std::ostream_iterator<int>(std::cout, " "));std::cout<<'\n'; // output v2std::cout<<"v2 : ";std::copy(v2.begin(), v2.end(), std::ostream_iterator<int>(std::cout, " "));std::cout<<'\n'; // merge std::merge(v1.begin(), v1.end(), v2.begin(), v2.end(), std::back_inserter(dst)); // outputstd::cout<<"dst: ";std::copy(dst.begin(), dst.end(), std::ostream_iterator<int>(std::cout, " "));std::cout<<'\n';}
Output:
v1 : 0 0 2 2 3 3 3 6 7 9 v2 : 1 2 5 5 6 6 6 6 7 9 dst: 0 0 1 2 2 2 3 3 3 5 5 6 6 6 6 6 7 7 9 9
[modifica]Vedi anche
unisce due gamme ordinate in-place Original: merges two ordered ranges in-place The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (funzione di modello) | |
ordina una serie in ordine crescente Original: sorts a range into ascending order The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (funzione di modello) | |
Ordina un intervallo di elementi, mantenendo ordine tra elementi uguali Original: sorts a range of elements while preserving order between equal elements The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (funzione di modello) |