rotate array without using temp/global/local storage

[quiz123]

Hi folks,
I have a problem. my function call is
void Rotate_n(int array[], int arraySize,int n);
//precondition: arraysize>=1 && n>=0 && n<=arraySize
//post condition: Values in the arrary are rotated forward(left to right)
by n positions.
eg: if the original array is {1,2,3,4,5}
then, rotate_n(array, 5,1); will make it{5,1,2,3,4}
my problem is, how do i manipulate the array without using temp??
Can anyone give me a pointer as to how i can achieve the same?
my line of thoughts is, to manipulate the "index" of the array as opposed to the contents/values stored in the array.


thx
quiz123(fairly new to C++)

[horace1]

if you are using C++ you could write your own class which could overload operator[] to map the supplied index to the actual index. Would there be a requirement to add/delete elements - if so this would add a layer of complexity.

The easy alternative is to shuffle the array elements to get the new origin to iindex 0 - however, you would need to use a temporary variable durring the exchanging of elements.

[kvbreddy]

hi,
Here is the solution... for ur problem
It is perfectly based on ur requirement

#include<stdio.h>
 
void rotate_n(int *array, int size, int n)
{
   int ii, jj;
 
   for (ii = 1; ii <= n; ii++)
   {
     for (jj = size-1; jj > 0; jj--)
     {
       /* swapping the array[jj] and array[jj-1] elements without
          using temporary variable */
        array[jj-1] = array[jj-1] + array[jj];
        array[jj] = array[jj-1] - array[jj];
        array[jj-1] = array[jj-1] - array[jj];
     }
   }
 
   return;
}
 
 
int main()
{
    int x[5] = {1,2,3,4,5}, n, ii;
 
    printf("Enter n value : \n");
    scanf("%d", &n);
 
    rotate_n(x, 5, n);
 
    printf("After swapping\n");
    for (ii = 0; ii < 5; ii++)
    {
      printf("%5d", x[ii]);
    }
    printf("\n");
 
    return 0;
}

[quiz123]

thanks for your prompt replies. It finally made sense.