A 5 digit positive integer is entered through the keyboard how to write a function in C to calculate sum of digits of the 5 digits number by using recursion and without using recursion?

Answer 1

#include <stdio.h>

int digit_sum(int);

int digit_sum_rec(int);

main()

{

int num;

printf("Enter 5 digit positive integer. : ");

scanf("%d",&num);

printf("The sum of the digits is: %d\n",digit_sum(num));

printf("The sum of the digits is (calculated recursively): %d\n",

digit_sum_rec(num));

}

int digit_sum(int n)

{

int t=0;

while(n) {

t+=n%10;

n/=10;

}

return t;

}

int digit_sum_rec(int n)

{

if(n==0) return 0;

return (n%10)+digit_sum_rec(n/10);

}