Untitled

How to convert an iterative algorithm to recursive solution
double A;
int B;
double previous=1;
double answer;

double equation(double A,int B){
 for(int i=1; i<=B; i++){
  answer= (A*previous)/(i+A*previous);
  previous = answer;
 };
 return answer;
}

equation(A, B) =
    IF(B = 1)
        A/(1+A)
    ELSE
        (A*equation(B-1)) / (B+A*equation(B-1))

Equation A , B = Equation_internal( A, B , 1, 1)


Equation_internal (A , B , i , prev ) =
  case i <= B   : return  Equation_internal ( A , B , i+1 , (A* prev )/(i+A*prev) )
  otherwise return prev.

double equation(double A,int B);
double equation2(double A,int B, int curcount, double previous);


double A;
int B;
double previous=1;
double answer;

int main (int argc, const char * argv[])
{


   double toto= equation(5,3);

   double toto2= equation2(5,3,0,1);


    return 0;
}

double equation(double A,int B){
    for(int i=1; i<=B; i++){
        previous= (A*previous)/(i+A*previous);
    };
    return previous;
}

double equation2(double A,int B, int curcount, double previous){

    if (curcount == B) {
        return previous;
    }else{
        curcount++;
        previous= (A*previous)/(curcount+A*previous);

        return equation2(A,B,curcount,previous);
    }

}