С++ ЕНФ / LABA 2 / 2LB3

#include <iostream.h>
#include <conio.h>
#include <math.h>
float r(int);
float it(int,float);
void main()
{
 clrscr();
 int n=0; float k,s=0;
 cout<<"proga vichislyayushaya chastichnuyu summu ryada \n\n";
 cout<<"vvedite chislo n \n\n";
  cin>>k;
  n=k;
  while ((n<1)||(n!=k))//proverka na prinadlegnost k N
   {cout<<"n dolgno bit >=1 & celoe \n\n";
    cout<<"vvedite chislo n \n\n"; cin>>k; n=k;};
 cout<<"summa po rekursii = "<<r(n)<<endl;
  //vivod otveta po rekursii
 cout<<"summa po itteracii = "<<it(n,s)<<endl;
  //vivod otveta po itteracii
 getch();
}
float it(int n,float s)
 {
  for (float i=1;i<=n;i++)
  s+=(i+1.)/(2*i+1.);
  /*funkciya v cikle i ot 1 do n pribavlyaet
   k predidusheyi summe poluchivsheecya chastnoe*/
  return s;} //vozvrashaet s
float r(int n)
{ if (n==1) {return ((n+1.)/(2*n+1.));}
  else {return ((n+1.)/(2*n+1.)+r(n-1));};}
    //funkciya pribavlyaet k znacheniyu r(n) znach. r(n-1) poka n!=1