partial_sort_copy (STL Samples)
Viene illustrato come utilizzare la funzione della libreria di modelli (STL) standard di partial_sort_copy in Visual C++.
template<class InputIterator, RandomAccessIterator> inline
RandomAccessIterator partial_sort(
InputIterator First1,
InputIterator Last1,
RandomAccessIterator First2,
RandomAccessIterator Last2
)
Note
[!NOTA]
La classe/nomi di parametro nel prototipo non corrisponde alla versione nel file di intestazione.alcuni sono stati modificati per migliorare la leggibilità.
L'algoritmo di partial_sort_copy ordina gli elementi più piccoli n , dove n = min((Last1 - First1), (Last2 - First2)), della sequenza [First1, Last1) e le copie i risultati alla sequenza [First2, First2 + n].La versione di nonpredicate di partial_sort_copy utilizza operator< per i confronti.
Esempio
// partial_sort_copy.cpp
// compile with: /EHsc
// Illustrates how to use the partial_sort_copy function.
//
// Functions:
// partial_sort_copy : Sort the smallest N elements in a sequence
// and copy the resulting sequence
// to another sequence.
// disable warning C4786: symbol greater than 255 character,
// okay to ignore
#pragma warning(disable: 4786)
#include <iostream>
#include <algorithm>
#include <functional>
#include <vector>
using namespace std ;
int main()
{
const int VECTOR_SIZE = 8 ;
// Define a template class vector of int
typedef vector<int> IntVector ;
//Define an iterator for template class vector of strings
typedef IntVector::iterator IntVectorIt ;
IntVector Numbers(VECTOR_SIZE) ;
IntVector Result(4) ;
IntVectorIt start, end, it ;
// Initialize vector Numbers
Numbers[0] = 4 ;
Numbers[1] = 10;
Numbers[2] = 70 ;
Numbers[3] = 30 ;
Numbers[4] = 10;
Numbers[5] = 69 ;
Numbers[6] = 96 ;
Numbers[7] = 7;
start = Numbers.begin() ; // location of first
// element of Numbers
end = Numbers.end() ; // one past the location
// last element of Numbers
cout << "Before calling partial_sort_copy\n" << endl ;
// print content of Numbers
cout << "Numbers { " ;
for(it = start; it != end; it++)
cout << *it << " " ;
cout << " }\n" << endl ;
// sort the smallest 4 elements in the Numbers
// and copy the results in Result
partial_sort_copy(start, end, Result.begin(), Result.end()) ;
cout << "After calling partial_sort_copy\n" << endl ;
cout << "Numbers { " ;
for(it = start; it != end; it++)
cout << *it << " " ;
cout << " }\n" << endl ;
cout << "Result { " ;
for(it = Result.begin(); it != Result.end(); it++)
cout << *it << " " ;
cout << " }\n" << endl ;
}
Output
Before calling partial_sort_copy
Numbers { 4 10 70 30 10 69 96 7 }
After calling partial_sort_copy
Numbers { 4 10 70 30 10 69 96 7 }
Result { 4 7 10 10 }
Requisiti
intestazione: <algoritmo>