C++/STL Algorithms Modifying sequence operations/swap ranges
Версия от 14:21, 25 мая 2010; (обсуждение)
Содержание
- 1 Illustrating the generic swap_ranges algorithm
- 2 Swap elements in first five elements of an array with elements in last five elements
- 3 Use swap_ranges to mirror first three with last three elements
- 4 Use swap_ranges to swap elements in one container with corresponding elements in another container
Illustrating the generic swap_ranges algorithm
#include <iostream>
#include <cassert>
#include <algorithm>
#include <vector>
#include <string>
using namespace std;
int main()
{
string s("HELLO");
string s2("THERE");
vector<char> vector1(s.begin(), s.end());
vector<char> vector2(s2.begin(), s2.end());
// Swap the contents of vector1 and vector2:
swap_ranges(vector1.begin(), vector1.end(), vector2.begin());
for(int i=0;i<vector1.size();i++){
cout << vector1[i] ;
}
cout << "\n\n\n\n\n";
for(int i=0;i<vector2.size();i++){
cout << vector2[i] ;
}
return 0;
}
/*
THERE
HELLO
*/
Swap elements in first five elements of an array with elements in last five elements
#include <iostream>
using std::cout;
using std::endl;
#include <algorithm>
#include <iterator>
int main()
{
int a[ 10 ] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
std::ostream_iterator< int > output( cout, " " );
cout << "Array a contains:\n ";
std::copy( a, a + 10, output );
std::swap_ranges( a, a + 5, a + 5 );
std::copy( a, a + 10, output );
cout << endl;
return 0;
}
/*
Array a contains:
1 2 3 4 5 6 7 8 9 10 6 7 8 9 10 1 2 3 4 5
*/
Use swap_ranges to mirror first three with last three elements
/* 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;
deque<int> coll2;
INSERT_ELEMENTS(coll1,1,9);
INSERT_ELEMENTS(coll2,11,23);
PRINT_ELEMENTS(coll1,"coll1: ");
PRINT_ELEMENTS(coll2,"coll2: ");
// mirror first three with last three elements in coll2
swap_ranges (coll2.begin(), coll2.begin()+3, // first range
coll2.rbegin()); // second range
PRINT_ELEMENTS(coll2,"\ncoll2: ");
}
/*
coll1: 1 2 3 4 5 6 7 8 9
coll2: 11 12 13 14 15 16 17 18 19 20 21 22 23
coll2: 23 22 21 14 15 16 17 18 19 20 13 12 11
*/
Use swap_ranges to swap elements in one container with corresponding elements in another container
/* 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;
deque<int> coll2;
INSERT_ELEMENTS(coll1,1,9);
INSERT_ELEMENTS(coll2,11,23);
PRINT_ELEMENTS(coll1,"coll1: ");
PRINT_ELEMENTS(coll2,"coll2: ");
// swap elements of coll1 with corresponding elements of coll2
deque<int>::iterator pos;
pos = swap_ranges (coll1.begin(), coll1.end(), // first range
coll2.begin()); // second range
PRINT_ELEMENTS(coll1,"\ncoll1: ");
PRINT_ELEMENTS(coll2,"coll2: ");
if (pos != coll2.end()) {
cout << "first element not modified: "
<< *pos << endl;
}
}
/*
coll1: 1 2 3 4 5 6 7 8 9
coll2: 11 12 13 14 15 16 17 18 19 20 21 22 23
coll1: 11 12 13 14 15 16 17 18 19
coll2: 1 2 3 4 5 6 7 8 9 20 21 22 23
first element not modified: 20
*/