Merge branch 'release/v1.0.21.0'

Author: andersonkmi

README.md

@@ -34,8 +34,11 @@ to keep up with the language and learn how to use the Scala test library as well
 * Add binary
 * Contains duplicate
 * Middle of linked list
+* Jewels and stones
 
 ## Versions
+* v1.0.21.0 (10/07/2018) - Added Jewels and stones exercise.
+
 * v1.0.20.2 (10/06/2018) - Improved null argument handling for Middle of linked list exercise.
 
 * v1.0.20.1 (10/06/2018) - Improved null argument handling for Contains duplicate exercise.

build.sbt

@@ -5,7 +5,7 @@ lazy val root = (project in file(".")).
     inThisBuild(List(
       organization := "org.codecraftlabs",
       scalaVersion := "2.12.7",
-      version      := "1.0.20.2"
+      version      := "1.0.21.0"
     )),
     name := "leetcode-scala",
     libraryDependencies += scalaTest % Test,

src/main/scala/org/codecraftlabs/leetcode/JewelsAndStones.scala

@@ -0,0 +1,11 @@
+package org.codecraftlabs.leetcode
+
+object JewelsAndStones {
+  def numJewelsInStones(j: String, s: String): Int = {
+    val jewels = j.toSet
+    val stones = s.toList
+
+    val groupedStones = stones.groupBy(identity).mapValues(_.length)
+    groupedStones.filterKeys(jewels).values.sum
+  }
+}

src/test/scala/org/codecraftlabs/leetcode/JewelsAndStonesSpec.scala

@@ -0,0 +1,18 @@
+package org.codecraftlabs.leetcode
+
+import org.codecraftlabs.leetcode.JewelsAndStones.numJewelsInStones
+import org.scalatest.{FlatSpec, Matchers}
+
+class JewelsAndStonesSpec extends FlatSpec with Matchers {
+  it should "return 3 with jewels = 'aA' and stones = 'aAAbbbb'" in {
+    val jewels = "aA"
+    val stones = "aAAbbbb"
+    numJewelsInStones(jewels, stones) shouldEqual 3
+  }
+
+  it should "return 0 with jewels = 'c' and stones = 'aAAbbbb'" in {
+    val jewels = "c"
+    val stones = "aAAbbbb"
+    numJewelsInStones(jewels, stones) shouldEqual 0
+  }
+}