C Tutor... C Tutorial....: Write a recursive function to find sum of digits of any number input through keyboard.

Write a recursive function to find sum of digits of any number input through keyboard.

main()
{
int s, n;
printf("\nEnter any number:");
scanf("%d",&n);
s =sum(n);
printf("\n Sum of digits = %d",s);
}

sum(int n)
{
if(n<10)
return(n); else
return(n %10 + sum(n/10)) ;
}

Recursive function is generally used when basic process itself is reverse. For example conversion of decimal to binary. The remainders are printed is reverse order of occurrence.

Ex.
2 23 (10111)2
2111
2 5 11 2 2 1
2 1 0
0 |l

History Of C..

In the beginning was Charles Babbage and his Analytical Engine, a machine
he built in 1822 that could be programmed to carry out different computations.
Move forward more than 100 years, where the U.S. government in
1942 used concepts from Babbage’s engine to create the ENIAC, the first
modern computer.
Meanwhile, over at the AT&T Bell Labs, in 1972 Dennis Ritchie was working
with two languages: B (for Bell) and BCPL (Basic Combined Programming
Language). Inspired by Pascal, Mr. Ritchie developed the C programming
language.