deal with negative args and zero

contents/euclidean_algorithm/code/scala/euclidean.scala

@@ -1,20 +1,22 @@
 object Euclid {
 
- def euclid(a: Int, b: Int):Int =
- (a,b) match{
- case (x, y) if x < y => euclid(x, y-x)
- case (x, y) if x > y => euclid(x-y, y)
+ def euclid(a: Int, b: Int): Int =
+ (Math.abs(a), Math.abs(b)) match {
+ case (0, _) | (_, 0) => 0
+ case (x, y) if x < y => euclid(x, y - x)
+ case (x, y) if x > y => euclid(x - y, y)
  case _ => a
  }
 
- def euclid_mod(a: Int, b: Int):Int =
- b match{
+ def euclid_mod(a: Int, b: Int): Int =
+ b match {
  case 0 => a
  case _ => euclid_mod(b, a % b)
  }
 
- def main(args: Array[String]): Unit =
- println(euclid(135749,27482))
- println(euclid_mod(135749,27482))
+ def main(args: Array[String]): Unit = {
+ println(euclid(151 * 899, 151 * 182))
+ println(euclid_mod(151 * 899, 151 * 182))
+ }
 
-}
+}