23.
In the not recently used algorithm, what do the R bits and M bits refer to?

24.
While choosing the value of a and m (m is the no. of alphabets) in affine cipher it must be ensured that?

27.
What is the name given to the algorithm depicted in the pseudo code below?
procedure generate(n : integer, Arr : array):
    if n = 1 then
          output(Arr)
    else
        for i = 0; i <= n - 2; i ++ do
            generate(n - 1, Arr)
            if n is even then
                swap(Arr[i], Arr[n-1])
            else
                swap(Arr[0], Arr[n-1])
            end if
        end for
        generate(n - 1, Arr )
    end if

30.
What is the time complexity of the following recursive implementation to find the sum of digits of a number n?
#include<stdio.h>
int recursive_sum_of_digits(int n)
{
      if(n == 0)
        return 0;
      return _________;
}
int main()
{
      int n = 1201;
      int ans = recursive_sum_of_digits(n);
      printf("%d",ans);
      return 0;
}