2016 Update

Task/Stern-Brocot-sequence/Scala/stern-brocot-sequence.scala

@@ -0,0 +1,18 @@
+lazy val sbSeq: Stream[BigInt] = {
+  BigInt("1") #::
+  BigInt("1") #::
+  (sbSeq zip sbSeq.tail zip sbSeq.tail).
+  flatMap{ case ((a,b),c) => List(a+b,c) }
+}
+
+// Show the results
+{
+println( s"First 15 members: ${(for( n <- 0 until 15 ) yield sbSeq(n)) mkString( "," )}" )
+println
+for( n <- 1 to 10; pos = sbSeq.indexOf(n) + 1 ) println( s"Position of first $n is at $pos" )
+println
+println( s"Position of first 100 is at ${sbSeq.indexOf(100) + 1}" )
+println
+println( s"Greatest Common Divisor for first 1000 members is 1: " +
+  (sbSeq zip sbSeq.tail).take(1000).forall{ case (a,b) => a.gcd(b) == 1 } )
+}