Question

Check whether the given number is twisted prime using Recursion.

(A number is called a twisted prime number if it is a prime number and the reverse of this number is also a prime number.)

				
					For example,let's say 13 is the given number then as 13 is prime number and reverse of 13 is 31 which is also prime number therefore,
13 is a Twisted Prime number

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Code

Java

Python

Java

				
					import java.util.Scanner;
public class twistedPrimeUsingRecursion
{
    public static boolean isPrime(int n,int i)
    {
        if(n<=1)
        {
            return false;
        }
        else if(n==i)
        {
            return true;
        }
        else if(n%i==0)
        {
            return false;
        }
        else
        {
            return isPrime(n,i+1);
        }
    }

    public static int reverseOfNumber(int n,int reverse)
    {
        if(n==0)
        {
            return reverse;
        }
        else
        {
            reverse=reverse*10+(n%10);
            return reverseOfNumber(n/10,reverse);
        }
    }

    public static void main(String[] args)
    {
        int number=0,reversedNumber=0;

        Scanner sc=new Scanner(System.in);
        System.out.println("ENTER A NUMBER:");
        number=sc.nextInt();
        if(number<0)
        {
            System.out.println(number+" IS NOT A TWISTED PRIME NUMBER");
        }
        else
        {
            if(isPrime(number,2)==true)
            {
                reversedNumber=reverseOfNumber(number,0);
                if(isPrime(reversedNumber,2)==true)
                {
                    System.out.println(number+" IS A TWISTED PRIME NUMBER");
                }
                else
                {
                    System.out.println(number+" IS NOT A TWISTED PRIME NUMBER");
                }
            }
            else
            {
                System.out.println(number+" IS NOT A TWISTED PRIME NUMBER");
            }
        }

    }
}

Python

				
					def isPrime(n,i=2):
    if(n<=1):
        return False
    elif(i==n):
        return True
    elif(n%i==0):
        return False
    else:
        return isPrime(n,i+1)

def reverseOfNumber(n,reverse=0):
    if(n==0):
        return reverse
    else:
        rem=n%10
        reverse=reverse*10+rem
        return reverseOfNumber(n // 10,reverse)

if (__name__=='__main__'):
    number=int(input("Enter a number:"))
    if(number<0):
        print(number,"is not a Twisted Prime number")
    else:
        reversedNumber= reverseOfNumber(number)
        if(isPrime(number)==True and isPrime(reversedNumber)==True):
            print(number,"is a Twisted Prime number")
        else:
            print(number,"is not a Twisted Prime number")