A-M baby

Task/Factorial/Scala/factorial-1.scala

@@ -0,0 +1,6 @@
+def factorial(n: Int)={
+  var res = 1
+  for(i <- 1 to n)
+    res *=i
+  res
+}

Task/Factorial/Scala/factorial-2.scala

@@ -0,0 +1 @@
+def factorial(n: Int) = if(n == 0) 1 else n * factorial(n-1)

Task/Factorial/Scala/factorial-3.scala

@@ -0,0 +1 @@
+def factorial(n: Int) = (2 to n).foldLeft(1)(_*_)

Task/Factorial/Scala/factorial-4.scala

@@ -0,0 +1,5 @@
+// Note use of big integer support in this version
+
+implicit def IntToFac(i : Int) = new {
+  def ! = (2 to i).foldLeft(BigInt(1))(_*_)
+}

Task/Factorial/Scala/factorial-5.scala

@@ -0,0 +1,10 @@
+scala> implicit def IntToFac(i : Int) = new {
+     |   def ! = (2 to i).foldLeft(BigInt(1))(_*_)
+     | }
+IntToFac: (i: Int)java.lang.Object{def !: scala.math.BigInt}
+
+scala> 20!
+res0: scala.math.BigInt = 2432902008176640000
+
+scala> 100!
+res1: scala.math.BigInt = 93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000