C++ Tutorial/STL Algorithms Modifying sequence operations/reverse

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Reverse a stack of integers

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
   
int main()
{
  vector<int> v;
  unsigned int i;
   
  for(i=0; i<10; i++) v.push_back(i);
   
  cout << "Initial: ";
  for(i=0; i<v.size(); i++) 
     cout << v[i] << endl;
   
  reverse(v.begin(), v.end());
   
  for(i=0; i<v.size(); i++) 
    cout << v[i] << endl;
   
  return 0;
}

Reverse the order of the found element with value 3 and all following 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 <algorithm>
using namespace std;
int main()
{
    vector<int> coll;
    vector<int>::iterator pos;
    // insert elements from 1 to 6 in arbitrary order
    coll.push_back(2);
    coll.push_back(5);
    coll.push_back(4);
    coll.push_back(1);
    coll.push_back(6);
    coll.push_back(3);
    // find the first element with value 3
    pos = find (coll.begin(), coll.end(),  // range
                3);                        // value
    // reverse the order of the found element with value 3 and all following elements
    reverse (pos, coll.end());
    // print all elements
    for (pos=coll.begin(); pos!=coll.end(); ++pos) {
        cout << *pos << " ";
    }
    cout << endl;
}
2 5 4 1 6 3

Use reverse to reverse order from second to last element but one

/* 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> coll;
    INSERT_ELEMENTS(coll,1,9);
    PRINT_ELEMENTS(coll,"coll: ");
    // reverse order from second to last element but one
    reverse (coll.begin()+1, coll.end()-1);
    PRINT_ELEMENTS(coll,"coll: ");
}
coll: 1 2 3 4 5 6 7 8 9
coll: 1 8 7 6 5 4 3 2 9

Use reverse to reverse the order of 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> coll;
    INSERT_ELEMENTS(coll,1,9);
    PRINT_ELEMENTS(coll,"coll: ");
    // reverse order of elements
    reverse (coll.begin(), coll.end());
    PRINT_ELEMENTS(coll,"coll: ");
}
coll: 1 2 3 4 5 6 7 8 9
coll: 9 8 7 6 5 4 3 2 1

Using the STL generic reverse algorithm with a vector

#include <iostream>
#include <vector>
#include <cassert>
#include <algorithm> // For reverse
using namespace std;
template <typename Container>
Container make(const char s[])
{
  return Container(&s[0], &s[strlen(s)]);
}
int main()
{
  vector<char> vector1 = make< vector<char> >("abc");
  reverse(vector1.begin(), vector1.end());
  assert (vector1 == make< vector<char> >("cba"));
  return 0;
}
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