Data update

Task/First-class-environments/Java/first-class-environments.java

@@ -0,0 +1,75 @@
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+public final class FirstClassEnvironments {
+
+	public static void main(String[] aArgs) {
+		code();
+	}
+	
+	private static void code() {
+		do {
+	        for ( int job = 0; job < JOBS; job++ ) {
+	            switchTo(job);
+	            hailstone();
+	        }
+	        System.out.println();	
+	    } while ( ! allDone() );
+
+	    System.out.println(System.lineSeparator() + "Counts:");
+	    for ( int job = 0; job < JOBS; job++ ) {
+	        switchTo(job);
+	        System.out.print(String.format("%4d", count));
+	    }
+	    System.out.println();
+	}
+	
+	private static boolean allDone() {	
+		for ( int job = 0; job < JOBS; job++ ) {
+	        switchTo(job);
+	        if ( sequence > 1 ) {
+	        	return false;
+	        }
+	    }
+	    return true;
+	}
+	
+	private static void hailstone() {
+	    System.out.print(String.format("%4d", sequence));
+	    if ( sequence == 1 ) {
+	    	return;
+	    }
+	
+	    count += 1;
+	    sequence = ( sequence % 2 == 1 ) ? 3 * sequence + 1 : sequence / 2;
+	}
+	
+	private static void switchTo(int aID) {
+	    if ( aID != currentId ) {
+	        environments.get(currentId).seq = sequence;
+	        environments.get(currentId).count = count;
+	        currentId = aID;
+	    }
+	
+	    sequence = environments.get(aID).seq;
+	    count = environments.get(aID).count;
+	}	
+	
+	private static class Environment {
+		
+		public Environment(int aSeq, int aCount) {
+			seq = aSeq; count = aCount;
+		}
+		
+		private int seq, count;
+		
+	}
+	
+	private static int sequence, count, currentId;	
+	private static List<Environment> environments =
+		IntStream.rangeClosed(1, 12).mapToObj( i -> new Environment(i, 0 ) ).collect(Collectors.toList());
+	
+	private static final int JOBS = 12;
+
+}