Find all prime numbers
static Vector < Integer > addPrimes ( ) { int n = MAX ; boolean [ ] prime = new boolean [ n + 1 ] ; Arrays . fill ( prime , true ) ; for ( int p = 2 ; p * p <= n ; p ++ ) { if ( prime [ p ] == true ) { for ( int i = p * p ; i <= n ; i += p ) prime [ i ] = false ; } } Vector < Integer > ans = new Vector < Integer > ( ) ;