Smith Numbers in java

Java Programming Java8Java.IO Package

A composite number whose sum of digits equal to the sum of the digits of its prime factors.

Ex: 58 = 2 x 29
(5 + 8 = 12) (2+ 2 + 9 = 12)

Program

public class SmithNumbers {
   public static boolean isPrime(int number) {
      int loop;
      int prime = 1;
      for(loop = 2; loop < number; loop++) {
         if((number % loop) == 0) {
            prime = 0;
         }
      }
      if (prime == 1) {
         return true;
      } else {
         return false;
      }
   }
   public static ArrayList<Integer> primeFactors(int number) {
      int sum = 0;
      ArrayList al = new ArrayList();
      for(int i = 2; i< number; i++) {
         while(number % i == 0) {
            System.out.println(i+" ");
            al.add(i);
            number = number/i;
         }
      }
      if(number >2) {
         System.out.println(number);
         al.add(number);
      }
      return al;
   }
   public static void main(String args[]) {
      Scanner sc = new Scanner(System.in);
      System.out.println("Enter a number :");
      int num = sc.nextInt();
      int sum = 0;
     
      if(isPrime(num)) {
         System.out.println("Given number is not smith number ");
      } else {
         ArrayList<Integer> arrayList = primeFactors(num);
         System.out.println("Prime factors of the given number are"+arrayList);
         Iterator it = arrayList.iterator();
         
         while(it.hasNext()) {
            int n = (int) it.next();
            System.out.println(n);
            while(n!=0) {
               sum = sum+n%10;
               n = n/10;
            }
         }
         int temp = 0;
         while(num != 0) {
            temp = temp + num%10;
            num = num/10;
         }
         System.out.println("sum of the digits of the numbers of the prime factorization: "+sum);
         System.out.println("Sum of digits in the given number: "+temp);
         
         if(temp==sum) {
            System.out.println("Given number is a smith number");
         } else {
            System.out.println("Given number is not smith number ");
         }
      }
   }
}

Output

Enter a number :
648
2
2
2
3
3
3
3
Prime factors of the given number are[2, 2, 2, 3, 3, 3, 3]
2
2
2
3
3
3
3
sum of the digits of the numbers of the prime factorization: 18
Sum of digits in the given number: 18
Given number is a smith number
raja
Updated on 25-Jun-2020 12:19:59

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