June 2018 Update

Task/Pascals-triangle/Scala/pascals-triangle-1.scala

@@ -1,5 +1,5 @@
-def tri(row:Int):List[Int] = { row match {
-  case 1 => List(1)
-  case n:Int => List(1) ::: ((tri(n-1) zip tri(n-1).tail) map {case (a,b) => a+b}) ::: List(1)
-  }
-}
+  def tri(row: Int): List[Int] =
+    row match {
+      case 1 => List(1)
+      case n: Int => 1 +: ((tri(n - 1) zip tri(n - 1).tail) map { case (a, b) => a + b }) :+ 1
+    }

Task/Pascals-triangle/Scala/pascals-triangle-2.scala

@@ -1,2 +1,3 @@
-def prettytri(n:Int) = (1 to n) foreach {i=>print(" "*(n-i)); tri(i) map (c=>print(c+" ")); println}
-prettytri(5)
+def prettyTri(n:Int) = (1 to n) foreach {i => print(" "*(n-i)); tri(i) map (c => print(c + " ")); println}
+
+prettyTri(5)

Task/Pascals-triangle/Scala/pascals-triangle-3.scala

@@ -0,0 +1,10 @@
+object Blaise extends App {
+  def pascalTriangle(): Stream[Vector[Int]] =
+    Vector(1) #:: Stream.iterate(Vector(1, 1))(1 +: _.sliding(2).map(_.sum).toVector :+ 1)
+
+  val output = pascalTriangle().take(15).map(_.mkString(" "))
+  val longest = output.last.length
+
+  println("Pascal's Triangle")
+  output.foreach(line => println(s"${" " * ((longest - line.length) / 2)}$line"))
+}