Scala : move sqrt into sandbox and Scala : add recursion.scala

1 files changed, 28 insertions, 0 deletions

diff --git a/Scala/sandbox/sqrt.scala b/Scala/sandbox/sqrt.scala
new file mode 100644
index 0000000..2544425
--- /dev/null
+++ b/Scala/sandbox/sqrt.scala
@@ -0,0 +1,28 @@
+
+object Sqrt {
+
+  def abs(x:Double) = if (x < 0) -x else x
+
+  def sqrt(x: Double) = {
+
+    def sqrtIter(guess: Double): Double =
+      if (isGoodEnough(guess)) guess
+      else sqrtIter(improve(guess))
+
+    def isGoodEnough(guess: Double) =
+      abs(guess * guess - x ) /x < 0.001
+
+    def improve(guess: Double) =
+      (guess + x / guess) / 2
+
+    sqrtIter(1.0)
+  }
+
+  def run =
+    println(sqrt(2))
+    println(sqrt(0.001))
+    println(sqrt(0.1e-20))
+    println(sqrt(1.0e20))
+    println(sqrt(1.0e50))
+
+}