Java Program for Twisted Prime – Pencil Programmer

Problem: Write a Java program to check whether the given number is Twisted Prime or not.

A number is said to be Twisted Prime if it is a prime number and its reverse is also a prime number.

Example:

Steps to check Twisted Prime in Java:

Input a number.
Check if the number is prime.
If the number is prime, compute its reverse.
Check if the reverse is prime.
If both step-2 and step-4 are true, then the input number is Twisted Prime, else not.

Here is the implementation of the steps in Java:

import java.util.Scanner;

class Main {

public static void main(String[] args) {

Scanner in=new Scanner(System.in);

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

int n=in.nextInt();

if(isPrime(n)){

//Computing Reverse

int rev=0;

while(n>0){

rev=rev*10 + n%10;

n=n/10;

}

if(isPrime(rev))

System.out.println("Twisted Prime");

else

System.out.println("Not a Twisted Prime");

}

else

System.out.println("Not a Twisted Prime");

}

//Function to Check Prime Number

private static boolean isPrime(int n){

for(int i=2; i<(n/2); i++){

if(n%i==0)

return false;

}

return true;

}

Output:

Enter a number: 31 Twisted Prime

In the above program, the isPrime(int n) function returns true if the passed number (i.e. n) is a prime number, otherwise it returns false.

We use the isPrime(int n) to check whether the input and its reverse are prime or not.

If anyone of them is not a prime number then it means input is not a Twisted Prime.

If both the numbers are prime then the input is said to be a Twisted Prime number.

In this programming example, we learned to check Twisted Prime number in Java programming language.