Twin Prime Numbers between 1 and n | Java program to print all Twin Prime Numbers using Sieve of Eratosthenes ; Create a boolean array " prime [ 0 . . n ] " and initialize all entries it as true . A value in prime [ i ] will finally be false if i is Not a prime , else true . ; If prime [ p ] is not changed , then it is a prime ; Update all multiples of p ; to check for twin prime numbers display th twin prime ; Driver Program to test above function ; Calling the function
import java . io . * ; class GFG { static void printTwinPrime ( 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 ] == true ) { for ( int i = p * 2 ; i <= n ; i += p ) prime [ i ] = false ; } } for ( int i = 2 ; i <= n - 2 ; i ++ ) { if ( prime [ i ] == true && prime [ i + 2 ] == true ) System . out . print ( " ▁ ( " + i + " , ▁ " + ( i + 2 ) + " ) " ) ; } } public static void main ( String args [ ] ) { int n = 25 ; printTwinPrime ( n ) ; } }