Adding Counting Sort in Scala

Jarvis@LNMIIT · Jarvis@LNMIIT · commit 490221210c7f · 2014-08-09T03:00:18.000+05:30
diff --git a/Counting_Sort/Scala/aayushKumarJarvis/CountingSort.scala b/Counting_Sort/Scala/aayushKumarJarvis/CountingSort.scala
@@ -0,0 +1,13 @@
+
+class CountingSort {
+
+  def countSort(listToBeSorted: List[Int], minValue: Int, maxValue: Int): List[Int] =
+
+    listToBeSorted.foldLeft(Array.fill(maxValue - minValue + 1)(0)) { (arr, n) =>
+      arr(n - minValue) += 1
+      arr
+    }.zipWithIndex.foldLeft(List[Int]()) {
+      case (lst, (cnt, ndx)) => List.fill(cnt)(ndx + minValue) ::: lst
+    }.reverse
+}
+
diff --git a/Counting_Sort/Scala/aayushKumarJarvis/CountingSortTest.scala b/Counting_Sort/Scala/aayushKumarJarvis/CountingSortTest.scala
@@ -0,0 +1,12 @@
+import org.scalatest.{Matchers, FunSuite}
+
+class CountingSortTest extends FunSuite with Matchers {
+
+  test("generateCountList should generate") {
+    val objectForCountingSort = new CountingSort
+
+    objectForCountingSort.countSort(List(11,1,22,33,23),1,33) should be(List(1,11,22,23,33))
+    objectForCountingSort.countSort(List(1,2,3,4,5,6,7,8,9),1,9) should be(List(1,2,3,4,5,6,7,8,9))
+  }
+}
+
