1. /* A 5-digit positive integer is entered through the keyboard, write a
function to calculate sum of digits of the 5-digit number:
(1) Without using recursion
(2) Using recursion */
#include<stdio.h>
#include<conio.h>
void main() {
long int num,s=0,ch,sum;
clrscr();
printf("Enter any number: ");
scanf("%ld",&num);
printf("nnChoose: 1: obtain sum of digits non-recursivelynn");
printf(" 2: obtain sum of digits recursivelynnn");
printf("Your choice: ");
ch=getche();
switch(ch) {
case '1':
while(num!=0) {
s=s+(num%10);
num=num/10;
}
printf("nnnsum of digits = %dn",s);
break;
case '2':
s=sum+num;
printf("nnnSum of digits = %dn",s);
break;
}
getch();
}
sum(long n) {
2. static s=0;
if(n==0)
return s;
else {
s=s+n%10;
n=sum(n/10);
return n;
}
}
Out Put
/* Write a recursive function to obtain the first 25 numbers of a
Fibonacci sequence. In a Fibonacci sequence the sum of two successive
terms gives the third term. Following are the first few terms of the
Fibonacci sequence:
1 1 2 3 5 8 13 21 34 55 89... */
#include<stdio.h>
#include<conio.h>
void main() {
unsigned i,num=25,c=1,fib;
clrscr();
for(i=0;i<num;i++) {
printf("%u ",fib*c);
c++;
}
