///// A

#include<stdio.h>
#include<conio.h>
int r(int n)
{
    int r1;
    if(n==0)
    r1=6;
    else
    r1=n*r(n-1);
    return(r1);
}
main()
{
      printf("Result = %d",r(9));
      getch();
}

///// B

#include<stdio.h>
#include<conio.h>
float r(int n,float x)
{
      float r2;
      if (n==0)
      r2=0.0;
      else
      r2=x+r(n-1,x);
      return(r2);
}
main()
{
      printf("Result = %f",r(9,3.2));
      getch();
}

///// C

#include<stdio.h>
#include<conio.h>
int r (int n)
{
    int r1;
    if(n<2)
    r1=0;
    else
    r1=1+r(n/2);
    return(r1);
}
main()
{
      printf("Result = %d",r(9));
      getch();
}

///// D

#include<stdio.h>
#include<conio.h>
    int r(int n)
{
    int r1;
    if(n==0)
    r1=0;
    else
    r1=r(n/10)+n;
    return(r1);
}
main()
{
      printf("Result = %d",r(9));
      getch();
}

///// E

#include<stdio.h>
#include<conio.h>
int r (int n)
{
    int r1;
    if(n<=0)
    r1=r(-n);
    else
    if(n<10)
    r1=n;
    else
    r1=r(n/10);
    return(r1);
}
main()
{
      printf("Result = %d",r(9));
      getch();
}

///// END