в 14:21, 25 мая 2010

2010-05-25T14:21:06Z

Admin: 1 версия: Импорт контента...

2010-05-25T10:28:19Z

1 версия: Импорт контента...

Новая страница

==Use stable_partition algorithms: preserving relative order in each group==

<source lang="cpp">

#include <algorithm>
#include <vector>
#include <string>
#include <iostream>
#include <iterator>
using namespace std;
bool above40(int n) { return (n > 4); }
int main()
{
const int N = 7;
int array0[N] = {5, 3, 1, 7, 6, 4, 2};
int array1[N];
copy(&array0[0], &array0[N], &array1[0]);
ostream_iterator<int> out(cout, " ");
cout << "Original sequence: ";
copy(&array1[0], &array1[N], out); cout << endl;
// Partition array1, putting numbers greater than 4
// first, followed by those less than or equal to 4,
// preserving relative order in each group:
int* split = stable_partition(&array1[0], &array1[N], above40);
cout << "Result of stable partitioning: ";
copy(&array1[0], split, out); cout << "| ";
copy(split, &array1[N], out); cout << endl;
return 0;
}
/*
Original sequence: 5 3 1 7 6 4 2
Result of stable partitioning: 5 7 6 | 3 1 4 2
*/
</source>

==Use stable_partition and partition==

<source lang="cpp">

/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
#include <iostream>
#include <vector>
#include <deque>
#include <list>
#include <set>
#include <map>
#include <string>
#include <algorithm>
#include <iterator>
#include <functional>
#include <numeric>
/* PRINT_ELEMENTS()
* - prints optional C-string optcstr followed by
* - all elements of the collection coll
* - separated by spaces
*/
template <class T>
inline void PRINT_ELEMENTS (const T& coll, const char* optcstr="")
{
typename T::const_iterator pos;
std::cout << optcstr;
for (pos=coll.begin(); pos!=coll.end(); ++pos) {
std::cout << *pos << " ";
}
std::cout << std::endl;
}
/* INSERT_ELEMENTS (collection, first, last)
* - fill values from first to last into the collection
* - NOTE: NO half-open range
*/
template <class T>
inline void INSERT_ELEMENTS (T& coll, int first, int last)
{
for (int i=first; i<=last; ++i) {
coll.insert(coll.end(),i);
}
}
using namespace std;
int main()
{
vector<int> coll1;
vector<int> coll2;
INSERT_ELEMENTS(coll1,1,9);
INSERT_ELEMENTS(coll2,1,9);
PRINT_ELEMENTS(coll1,"coll1: ");
PRINT_ELEMENTS(coll2,"coll2: ");
cout << endl;
// move all even elements to the front
vector<int>::iterator pos1, pos2;
pos1 = partition(coll1.begin(), coll1.end(), // range
not1(bind2nd(modulus<int>(),2))); // criterion
pos2 = stable_partition(coll2.begin(), coll2.end(), // range
not1(bind2nd(modulus<int>(),2))); // crit.
// print collections and first odd element
PRINT_ELEMENTS(coll1,"coll1: ");
cout << "first odd element: " << *pos1 << endl;
PRINT_ELEMENTS(coll2,"coll2: ");
cout << "first odd element: " << *pos2 << endl;
}
/*
coll1: 1 2 3 4 5 6 7 8 9
coll2: 1 2 3 4 5 6 7 8 9
coll1: 8 2 6 4 5 3 7 1 9
first odd element: 5
coll2: 2 4 6 8 1 3 5 7 9
first odd element: 1
*/

</source>

← Предыдущая	Версия 14:21, 25 мая 2010
(нет различий)

C++/STL Algorithms Modifying sequence operations/stable partition - История изменений

в 14:21, 25 мая 2010

Admin: 1 версия: Импорт контента...