Write a program to accept a number and check and display whether it is a Niven number or not.
(Niven number is that number which is divisible by its sum of digits.).
Example:
Consider the number 126. Sum of its digits is 1 + 2 + 6 = 9 and 126 is divisible by 9.
import java.util.Scanner;
public class RAnsariNivenNumber
{
public void checkNiven() {
Scanner in = new Scanner(System.in);
System.out.print("Enter number: ");
int num = in.nextInt();
int orgNum = num;
int digitSum = 0;
while (num != 0) {
int digit = num % 10;
num /= 10;
digitSum += digit;
}
/*
* digitSum != 0 check prevents
* division by zero error for the
* case when users gives the number
* 0 as input
*/
if (digitSum != 0 && orgNum % digitSum == 0)
System.out.println(orgNum + " is a Niven number");
else
System.out.println(orgNum + " is not a Niven number");
}
}
First read the algorithm, then study the program code line by line. After that, compare the code with the output and finally go through the explanation. This approach helps learners understand both the logic and the implementation properly.
After understanding this example, try to rewrite the same program without looking at the code. Then change some values or logic and run it again. This helps improve confidence and keeps learners engaged on the page for longer.