rotate (STL Samples)

Illustrates how to use the rotate Standard Template Library (STL) function in Visual C++.

template<class ForwardIterator> inline
   void rotate(
      ForwardIterator First,
      ForwardIterator Middle,
      ForwardIterator Last
   )

Remarks

Notes

The class/parameter names in the prototype do not match the version in the header file. Some have been modified to improve readability.

The rotate algorithm rotates the elements in the range [First, Last) to the right by n positions, where n = Middle - First.

Example

// rotate.cpp
// compile with: /EHsc
// Illustrates how to use the rotate function.
//
// Functions:
//    rotate - Rotate the items in a sequence by n positions.
//
//////////////////////////////////////////////////////////////////////

// disable warning C4786: symbol greater than 255 character,
// okay to ignore
#pragma warning(disable: 4786)

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <functional>

using namespace std;

int main()
{
   const int VECTOR_SIZE = 8;

   // Define a template class vector of strings
   typedef vector<string> StrVector;

   //Define an iterator for template class vector of strings
   typedef StrVector::iterator StrVectorIt;

   StrVector Tongue_Twister(VECTOR_SIZE);

   StrVectorIt start, end, middle, it;

   // location of first element of Tongue_Twister
   start = Tongue_Twister.begin();   

   // one past the location last element of Tongue_Twister
   end = Tongue_Twister.end();       


   // Initialize vector Tongue_Twister
   Tongue_Twister[0] = "she";
   Tongue_Twister[1] = "sells";
   Tongue_Twister[2] = "sea";
   Tongue_Twister[3] = "shells";
   Tongue_Twister[4] = "by";
   Tongue_Twister[5] = "the";
   Tongue_Twister[6] = "sea";
   Tongue_Twister[7] = "shore";

   middle = start + 3;  // start position for rotating elements

   cout << "Before calling rotate" << endl;

   // print content of Tongue_Twister
   cout << "Try this Tongue Twister:";
   for (it = start; it != end; it++)
      cout << " " << *it;

   // rotate the items in the vector Tongue_Twister by 3 positions
   rotate(start, middle, end);

   cout << endl << "After calling rotate" << endl;

   // print content of Tongue_Twister
   cout << "Now try the rotated Tongue Twister:";
   for (it = start; it != end; it++)
      cout << " " << *it;
   cout << endl;
}

Output

Before calling rotate
Try this Tongue Twister: she sells sea shells by the sea shore
After calling rotate
Now try the rotated Tongue Twister: shells by the sea shore she sells sea

Requirements

Header: <algorithm>

See Also

Concepts

Standard Template Library Samples