ISC COMPUTER SCIENCE PRACTICAL 2016 QUESTION 1 : CIRCULAR PRIME

Question:

A Circular Prime is a prime number that remains prime under cyclic shifts of its digits. When the leftmost digit is removed and replaced at the end of the remaining string of digits, the generated number is still prime. The process is repeated until the original number is reached again.
A number is said to be prime if it has only two factors I and itself.

Example:
131
311
113
Hence, 131 is a circular prime.

Test your program with the sample data and some random data:

Example 1

INPUT :N = 197
OUTPUT:
197
971
719
197 IS A CIRCULAR PRIME

Example 2

INPUT :N = 1193
OUTPUT:
1193
1931
9311
3119
1193 IS A CIRCULAR PRIME

Example 3

INPUT :N = 29
OUTPUT:
29
92
29 IS NOT A CIRCULAR PRIME

import java.util.*;

public class ISC2016Q1 {

       public static void main(String[] args) {

       int N;

    Scanner in = new Scanner(System.in);

    System.out.println("Enter the value of N");

    N = in.nextInt();

    circularPrime obj = new circularPrime(N);

    obj.digitExtraction();

    obj.circularNumberGenerator();

    System.out.println("OUTPUT");

    obj.circularPrimeTest();

    in.close();

       }

}

class circularPrime {

      

       public void circularPrimeTest() {

             flag = true;

             for(int i=0;i<number_length;i++) {

                    if(!isPrime(circular_numbers[i])){ // checking whether each circular number is prime or not

                          flag = false;

                          break;

                    }

             }

             for(int j=0;j<number_length;j++) {

                    System.out.println("        "+circular_numbers[j]);

             }

             if(flag==true)

                    System.out.println(number+"  IS A CIRCULAR PRIME");

             else

                    System.out.println(number+"  IS NOT A CIRCULAR PRIME");

       }

      

 public void circularNumberGenerator() {

        int temp,k;

        for(int i=0;i<number_length;i++) {

              temp = 0;

              k = number_length-1;

              for(int j=0;j<number_length;j++)

                     temp = temp + digits_of_number[(i+j)%number_length]*(int)Math.pow(10,k--); // generating circular numbers

                     circular_numbers[i]=temp;

              }

   }

public void digitExtraction() {

       int temp = number;

       for(int i=number_length-1; i>=0; i--) {

             digits_of_number[i] = temp%10;

             temp /=10;

             }

   }

private boolean isPrime(int n) {

       flag = true;

       if (n==1)

             return false;

  else {

         for(int i = 2; i<=n/2;i++)

                   if(n%i==0) {

                      flag=false;

                      break;

                   }

         return(flag);

       }

  }

circularPrime(int N){

       int temp=1;

       number = N;

       number_length = 0;

       while (temp <= number) {  // int length = String.valueOf(number).length(); can be also used

      number_length++;

      temp *= 10;

         }

       digits_of_number = new int[number_length];

       circular_numbers = new int[number_length];

  }

 private boolean flag;

 private int number;

 private int number_length;

 private int[] digits_of_number;

 private int[] circular_numbers;

 }