Example: SumOfTwoPrimes in Java

// SumOfTwoPrimes
import java.util.Scanner;

// Main class containing the entry point of the program
public class Main {

    // Method to check if a number is prime
    public static boolean isPrime(int num) {
        if (num <= 1) {
            return false;
        }
        for (int i = 2; i <= Math.sqrt(num); i++) {
            if (num % i == 0) {
                return false;
            }
        }
        return true;
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        // Step 1: Get input from the user
        System.out.print("Enter a positive integer: ");
        int n = scanner.nextInt();

        if (n <= 2) {
            System.out.println("Please enter an integer greater than 2.");
            scanner.close();
            return;
        }

        // Step 2: Initialize a flag to track if a solution is found
        boolean found = false;

        // Step 3: Iterate from 2 up to n/2
        for (int i = 2; i <= n / 2; i++) {
            // Step 4: Check if 'i' is a prime number
            if (isPrime(i)) {
                // Step 5: Calculate the remaining part
                int remaining = n - i;
                // Step 6: Check if the remaining part is also a prime number
                if (isPrime(remaining)) {
                    System.out.println(n + " can be expressed as the sum of two prime numbers: " + i + " + " + remaining);
                    found = true;
                    break; // Found a pair, no need to check further
                }
            }
        }

        // Step 7: If no pair was found, print the appropriate message
        if (!found) {
            System.out.println(n + " cannot be expressed as the sum of two prime numbers.");
        }

        scanner.close();
    }
}