Question

Write a program to input two numbers and check whether they are twin prime numbers or not. 

Hint: Twin prime numbers are the prime numbers whose difference is 2. 
For example, (5, 7), (11, 13), ............................ and so on.

Answer 1

import java.util.*;
public class Q2
{public static void main(String args[])
{   int a, b, cnt1 = 0, cnt2 = 0;
    Scanner sn = new Scanner(System.in);
System.out.printin("Enter two integers");
    a = sn.nextInt();
    b = sn.nextInt();

for (int i = 1; i <= a / 2; i++)
{   if (a % i == 0)
    cntl++; // for prime numbers cnt will be 1 when the loop runs till half the number
    } 
for(int j = 1; j <= b / 2; j++)
   {
  if (b % j == 0)
  cnt2++; // for prime numbers cnt will be 1
  }
if (cnt1 == 1 && cnt2 == 1 && Math.abs(a - b) == 2)
System.out.println("The numbers are Twin Prime");
  else
System.out.printIn("The numbers are not Twin Prime");
  }}