add single number III exercise

Author: andersonkmi

src/main/scala/org/sharpsw/leetcode/SingleNumberIII.scala

@@ -0,0 +1,7 @@
+package org.sharpsw.leetcode
+
+object SingleNumberIII {
+  def singleNumber(nums: Array[Int]): Array[Int] = {
+    nums.groupBy(l => l).mapValues(_.length).filter(p => p._2 == 1).keys.toArray
+  }
+}

src/test/scala/org/sharpsw/leetcode/SingleNumberIIISpec.scala

@@ -0,0 +1,12 @@
+package org.sharpsw.leetcode
+
+import org.scalatest.{FlatSpec, Matchers}
+
+class SingleNumberIIISpec extends FlatSpec with Matchers {
+  "Given nums = [1, 2, 1, 3, 2, 5]" should "return [3, 5]" in {
+    val nums = Array[Int](1, 2, 1, 3, 2, 5)
+    val result = SingleNumberIII.singleNumber(nums).sorted
+    result should have length 2
+    result should be (Array(3, 5))
+  }
+}