Data update

Task/Summarize-primes/Java/summarize-primes.java

@@ -0,0 +1,59 @@
+public final class SummarizePrimes {
+
+	public static void main(String[] args) {
+		final int start = 1;
+	    final int finish = 1_000;
+
+	    int sum = 0;
+	    int count = 0;
+	    int summarizedCount = 0;
+
+	    for ( int p = start; p < finish; p++ ) {
+	        if ( isPrime(p) ) {
+	            count += 1;
+	            sum += p;
+	
+	            if ( isPrime(sum) ) {
+	            	String word = ( count == 1 ) ? " prime" : " primes";
+	                System.out.println(
+	                	"The sum of " + count + word + " in [2, " + p + "] is " + sum + ", which is also prime.");
+	                summarizedCount++;
+	            }
+	        }
+	    }
+	
+	    System.out.println(System.lineSeparator() +
+	    	"There are " + summarizedCount + " summarized primes in [" + start + ", " + finish + "].");
+	}
+	
+	private static boolean isPrime(int number) {
+		if ( number < 2 ) {
+	        return false;
+	    }
+		
+	    if ( number % 2 == 0 ) {
+	        return number == 2;
+	    }
+	
+	    if ( number % 3 == 0 ) {
+	        return number == 3;
+	    }
+
+	    int test = 5;
+	    while ( test * test <= number ) {
+	        if ( number % test == 0 ) {
+	            return false;
+	        }
+	
+	        test += 2;	
+	        if ( number % test == 0 ) {
+	            return false;
+	        }
+	
+	        test += 4;
+	    }
+	
+		return true;
+	}
+
+}