Question

write a program in java to print prime factorisation

Answer 1

Prime factors of a number are those factors which are prime in nature and by which the number itself is completely divisible (1 will not be taken as prime number).

Few such numbers are:
Prime Factors of 24 are 2, 2, 2, 3
Prime Factors of 6 are 2, 3

Solution:
/**
 * The class PrimeFactors inputs a number and prints all its PrimeFactors

 * @author : www.javaforschool.com

 * @Program Type : BlueJ Program - Java

 */

import java.io.*;

class PrimeFactors

{

public static void main(String args[]) throws IOException

{

BufferedReader br=new BufferedReader(new InputStreamReader(System.in));

int n;

System.out.print("Enter a Number : ");

n=Integer.parseInt(br.readLine());

System.out.print("The Prime Factors of "+n+" are : ");

int i=2;

while(n>1)

  {

   if(n%i == 0)

    {

     System.out.print(i+" ");

     n=n/i;

    }

   else

    i++;

  }

}

}

Output:

Enter a Number : 378
The Prime Factors of 378 are: 2  3  3  3  7