تمرين برمجة جافا بسيط | Twin primes USING JAVA | مع شرح فيديو

(Twin primes) Twin primes are a pair of prime numbers that differ by 2. For example,

3 and 5 are twin primes, 5 and 7 are twin primes, and 11 and 13 are twin primes.

Write a program to find all twin primes less than 1,000. Display the output as follows:

(3, 5)

(5, 7)

الكود كاملا:

public class Java4 {

    public static void main(String[] args) {
       int n = 1000; 
        TwinPrime(n); 
    }
    static void TwinPrime(int n) 
    { 
        
        boolean prime[] = new boolean[n + 1]; 
          
        for (int i = 0; i <= n; i++) 
            prime[i] = true; 
  
        for (int p = 2; p * p <= n; p++) { 
              
            // If prime[p] is not changed, 
            // then it is a prime 
            if (prime[p] == true) { 
                  
                // Update all multiples of p 
                for (int i = p * 2; i <= n; i += p) 
                    prime[i] = false; 
            } 
        } 
  
        // to check for twin prime numbers 
        // display th twin prime 
        for (int i = 2; i <= n - 2; i++) { 
  
            if (prime[i] == true && 
                prime[i + 2] == true) 
              
                // Display the result 
                System.out.println(" (" + i + ", " + 
                                   (i + 2) + ")"); 
        } 
    } 
    
}

وهذا شرح الكود: