18.13. Write a function that gets any positive integer and returns digital root.

#include<stdio.h>
#include<conio.h>
int Sum(int n)
{
int s=0;

while(n>0)

{

s=s+n%10;

n=n/10;

}

return s;

}

int Root(int n)

{

while(n>9)

s=Sum(n);

return n;

}
void main ()
{
int n;
clrscr();
printf("Enter any positive integer: ");
scanf ("%d", &n);
printf("Digital Root= %d", Root(n)) ;
getch ();
}