partition (STL Samples)
Illustre comment utiliser la fonction de bibliothèque de types (STL) Standard de partition dans Visual C++.
template<class BidirectionalIterator, class Predicate> inline
BidirectionalIterator partition(
BidirectionalIterator First,
BidirectionalIterator Last,
Predicate Predicate
)
Notes
[!REMARQUE]
Les noms de classes/paramètre dans le prototype ne correspondent pas à la version du fichier d'en-tête.certains ont été modifiés pour améliorer la lisibilité.
L'algorithme de partition réorganise des éléments dans la plage [First, Last) tels que les éléments pour lesquels le retourne true d' Predicate sont avant les éléments pour lesquels le prédicat retourne false.L'algorithme retourne un itérateur positionné au premier élément pour lequel Predicate retourne false.
Exemple
// partition.cpp
// compile with: /EHsc
// Illustrates how to use the partition function.
//
// Functions:
// partition - Partition a range using a predicate.
//
// begin - Returns an iterator that points to the first element
// in a sequence.
//
// end - Returns an iterator that points one past the end of
// a sequence.
//
// bind2nd - Returns true for elements for which the condition
// is true.
// disable warning C4786: symbol greater than 255 character,
// okay to ignore
#pragma warning(disable: 4786)
#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
using namespace std;
int main()
{
const int VECTOR_SIZE = 8 ;
// Define a template class vector of integers
typedef vector<int > IntVector ;
//Define an iterator for template class vector of integer
typedef IntVector::iterator IntVectorIt ;
IntVector Numbers(VECTOR_SIZE) ; //vector containing numbers
IntVectorIt start, end, it ;
start = Numbers.begin() ; // location of first
// element of Numbers
end = Numbers.end() ; // one past the location
// last element of Numbers
//Initialize vector Numbers
Numbers[0] = 6 ;
Numbers[1] = 20 ;
Numbers[2] = 10 ;
Numbers[3] = 15 ;
Numbers[4] = 12 ;
Numbers[5] = 7 ;
Numbers[6] = 9 ;
Numbers[7] = 10 ;
cout << "Before calling partition" << endl ;
// print content of Numbers
cout << "Numbers { " ;
for(it = start; it != end; it++)
cout << *it << " " ;
cout << " }\n" << endl ;
// partition the sequence such that all the elements
// less than 11 appear before all the elements greater than 11
it = partition(start, end, bind2nd(less<int>(), 11)) ;
cout << "After calling partition" << endl ;
// print content of Numbers
cout << "Numbers { " ;
for(it = start; it != end; it++)
cout << *it << " " ;
cout << " }\n" << endl ;
}
Sortie
Before calling partition
Numbers { 6 20 10 15 12 7 9 10 }
After calling partition
Numbers { 6 10 10 9 7 12 15 20 }
Configuration requise
en-tête : <algorithm>