Right-rotate a sequence by using reverse iterators with the rotate() algorithm.
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
void show(const char *msg, vector<int> vect);
int main(){
vector<int> v;
for(int i=0; i<10; i++)
v.push_back(i);
show("Original order: ", v);
rotate(v.rbegin(), v.rbegin()+2, v.rend());
show("Order after two right-rotates: ", v);
return 0;
}
void show(const char *msg, vector<int> vect) {
cout << msg << endl;
for(unsigned i=0; i < vect.size(); ++i)
cout << vect[i] << endl;
}Rotate a vector: Rotate left one position
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
void show(const char *msg, vector<int> vect);
int main()
{
vector<int> v;
for(int i=0; i<10; i++) v.push_back(i);
show("Original order: ", v);
rotate(v.begin(), v.begin()+1, v.end());
show("Order after rotating left one position: ", v);
return 0;
}
void show(const char *msg, vector<int> vect) {
cout << msg << endl;
for(unsigned i=0; i < vect.size(); ++i)
cout << vect[i] << endl;
}Rotate left two places
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
void show(const char *msg, vector<int> vect);
int main()
{
vector<int> v;
for(int i=0; i<10; i++) v.push_back(i);
show("Original order: ", v);
rotate(v.begin(), v.begin()+2, v.end());
show("Order after rotating left two positions: ", v);
return 0;
}
void show(const char *msg, vector<int> vect) {
cout << msg << endl;
for(unsigned i=0; i < vect.size(); ++i)
cout << vect[i] << endl;
}Use rotate to rotate one element to the left
/* 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: ");
// rotate one element to the left
rotate (coll.begin(), // beginning of range
coll.begin() + 1, // new first element
coll.end()); // end of range
PRINT_ELEMENTS(coll,"one left: ");
}coll: 1 2 3 4 5 6 7 8 9
one left: 2 3 4 5 6 7 8 9 1
Use rotate to rotate so that element with value 4 is the beginning
/* 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: ");
// rotate so that element with value 4 is the beginning
rotate (coll.begin(), // beginning of range
find(coll.begin(),coll.end(),4), // new first element
coll.end()); // end of range
PRINT_ELEMENTS(coll,"4 first: ");
}coll: 1 2 3 4 5 6 7 8 9
4 first: 4 5 6 7 8 9 1 2 3
Use rotate to rotate two elements to the right
/* 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: ");
// rotate two elements to the right
rotate (coll.begin(), // beginning of range
coll.end() - 2, // new first element
coll.end()); // end of range
PRINT_ELEMENTS(coll,"two right: ");
}coll: 1 2 3 4 5 6 7 8 9
two right: 8 9 1 2 3 4 5 6 7
Use the generic rotate algorithm
#include <iostream>
#include <cassert>
#include <algorithm>
#include <vector>
#include <string>
using namespace std;
int main()
{
string s("Software Engineering ");
vector<char> vector1(s.begin(), s.end());
// Rotate the vector so that "Engineering " comes first:
rotate(vector1.begin(), vector1.begin() + 9,vector1.end());
for(int i=0;i<vector1.size();i++){
cout << vector1[i] ;
}
return 0;
}Engineering Software
