C++ Tutorial/STL Algorithms Modifying sequence operations/swap ranges

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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
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