MagicNumber.java

/*
Q13: Magic Number [Hard]
- Input: 1729
Output: Magic Number
- Input: 19
Output: Not Magic Number
A number is said to be a magic number, if the sum of its digits are calculated till a single digit recursively by adding the sum of the digits after every addition. If the single digit comes out to be 1,then the number is a magic number.  
*/
package week2;
import java.util.Scanner;
public class MagicNumber {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int digit, sum;
		while(n > 9) {
			sum = 0;
			while(n > 0) {
				digit = n %10;
				sum += digit;
				n /= 10;
			}
			n= sum;
		}
		if(n == 1) System.out.println("Magic Number");
		else System.out.println("Not Magic Number");
		sc.close();
	}
}