Question

Print Twin Prime numbers in given range using recursion

(Twin Primes are the prime numbers with a difference of 2.)

Example: (3 and 5),(5 and 7),(11 and 13) etc

Enter the lower value:-10
Enter the upper value:90
Twin Prime numbers between -10 and 90 :
( 3 , 5 )
( 5 , 7 )
( 11 , 13 )
( 17 , 19 )
( 29 , 31 )
( 41 , 43 )
( 59 , 61 )
( 71 , 73 )

Share code with your friends

Code

Java

Python

Java

import java.util.Scanner;
public class TwinPrimeInGivenRangeUsingRecursion
{
    public static boolean isPrime(int n,int i)
    {
        if(n<=1)
        {
            return false;
        }

        else if(i==n)
        {
            return true;
        }

        else if(n%i==0)
        {
            return false;
        }
        else
        {
            return  isPrime(n,(i+1));
        }
    }

    public static void main()
    {
        int lowerRange=0,upperRange=0,difference=0,i=0,firstNumber=0,secondNumber=0;
        boolean isFirstNumberPrime=false,isSecondNumberPrime=false;
        Scanner sc=new Scanner(System.in);
        System.out.println("ENTER LOWER VALUE:");
        lowerRange=sc.nextInt();
        System.out.println("ENTER UPPER VALUE:");
        upperRange=sc.nextInt();
        System.out.println("Twin Prime numbers between "+lowerRange+" and "+upperRange+":");
        for(i=lowerRange;i<=upperRange-2;i++)
        {
            firstNumber=i;
            secondNumber=i+2;
            isFirstNumberPrime=isPrime(firstNumber,2);
            isSecondNumberPrime=isPrime(secondNumber,2);

            if(isFirstNumberPrime==true)
            {
                if(isSecondNumberPrime==true)
                {
                    System.out.println("("+firstNumber+","+secondNumber+")");
                }
            }

        }

    }
}

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)

if(__name__=='__main__'):
    lowerRange=int(input("Enter the lower value:"))
    upperRange = int(input("Enter the upper value:"))
    print("Twin Prime numbers between",lowerRange,"and",upperRange,":")
    for i in range(lowerRange,upperRange-1):
        firstNumber=i
        secondNumber=i+2
        isFirstNumberPrime=isPrime(firstNumber)
        isSecondNumberPrime=isPrime(secondNumber)
        if(isFirstNumberPrime==True and isSecondNumberPrime==True):
            print("(",firstNumber,",",secondNumber,")")