Circular Prime Number – SchoolCodeHub

Circular Prime Number is a number whose all-circular permutations are Prime Numbers.

Prime Number is a number which is only divisible by 1 and the number itself i.e., it has no factors other than 1 and itself.

Example 1: 113. All possible circular permutations are 113, 131, 311. All of these are Prime Numbers. Hence it is a Circular Prime Number.

Example 2: 115. All possible circular permutations are 115, 151, 511. Since 115 and 511 are not Prime Numbers. Hence it is not a Circular Prime Number.

Java

import java.util.*;
public class CircularPrimeNumber
{
    public static void main(String args[])
    {
        int n=0,r=0,q=0,l=0,nCopy=0;
        Scanner sc=new Scanner(System.in);
        System.out.print("Enter a number: ");
        n=sc.nextInt();
        nCopy=n;
        while(n>0)
        {
            l++;
            n=n/10;
        }
        n=nCopy;
        for(int i=1;i<=l;i++)
        {
            for(int j=2;j<n;j++)
            {
                if(n%j==0)
                {
                    System.out.println(n+" is not a Circular Prime Number");
                    System.exit(1);
                }
            }
            r=n%10;
            q=n/10;
            n=(r*(int)Math.pow(10,l-1))+q;
        }
        System.out.println(n+" is a Circular Prime Number");
    }
}

Java