/*

Source File: LoopSum.c

Author: Yana

This program sums the digits of a non-negative integer.

Input:a a non-negative integer

Output: The sum of the digits of the given input number

Algorithm: Use division by 10 and modulo by 10 in order to

extract each time the least significant digit.

*/

#include<stdio.h>

int main(){

int number = 0; /* the input number */
int sum = 0; /* the sum of digits of the input */

/* input session */
printf("Please enter a non-negative integer number: ");
scanf("%d", &number);

/* find sum of digits of input number */
/* centinel-controlled repetition */
while( number > 0){
/* extract current LSG (least significant digit) and add it to sum. */
sum += number % 10;
number /= 10;
}

/* output result */
printf( "The sum of digits is: %d\n", sum);

return 0;

}