homework_6 - Рябцев Никита

homeworks/homework_5/src/main/scala/Exercises.scala

@@ -8,16 +8,37 @@ object Exercises {
   case class Dog(override val name: String) extends Animal
 
 
+  case class Shelter[+T <: Animal](list: List[T]) {
 
-  case class Shelter ...
+    private val _list = list
+    val getNames: List[String] = _list.map(animal => animal.name)
 
+    def +[A >: T <: Animal](animal: A): Shelter[A] = Shelter(_list :+ animal)
 
+    def ++[A >: T <: Animal](shelter: Shelter[A]): Shelter[A] = Shelter(_list ::: shelter.list)
+
+    def feed(meat: Food[T]): List[String] =
+      _list.map(animal => meat.feed(animal))
+  }
 
-  trait Food ...
 
-  case object Meat extends Food[Animal] ...
+  trait Food[-T <: Animal] {
+    val _name: String
 
-  case object Milk extends Food[Cat] ...
+    def feed(animal: T): String =
+      animal.name + " eats " + _name
+  }
+
+  case object Meat extends Food[Animal] {
+    override val _name = "meat"
+  }
 
-  case object Bread extends Food[Dog] ...
+  case object Milk extends Food[Cat] {
+    override val _name = "milk"
+  }
+
+
+  case object Bread extends Food[Dog] {
+    override val _name = "bread"
+  }
 }

homeworks/homework_6/src/main/scala/Exercises.scala

@@ -1,27 +1,53 @@
+import scala.annotation.tailrec
+
 object Exercises {
 
 
-  def reverse[T](seq: Seq[T]): Seq[T] = ???
+  def reverse[T](seq: Seq[T]): Seq[T] = seq match {
+    case element :: Nil => Seq(element)
+    case element :: tail => reverse(tail) :+ element
+  }
 
   /**
    * https://ru.wikipedia.org/wiki/Числа_Фибоначчи
    *
    * @param idx
    * @return
    */
-  def fibonacci4Index(idx: Int): Int = ???
-
-  def fibonacci(idx: Int): Seq[Int] = ???
+  def fibonacci4Index(idx: Int): Int = fibonacciAccumulator(0, 1, idx)
 
-  lazy val MORSE = Map("A" -> ".-", "B" -> "-...", "C" -> "-.-.", "D" -> "-..", "E" -> ".", "F" -> "..-.",
-                       "G" -> "--.", "H" -> "....", "I" -> "..", "J" -> ".---", "K" -> "-.-", "L" -> ".-..",
-                       "M" -> "--", "N" -> "-.", "O" -> "---", "P" -> ".--.", "Q" -> "--.-", "R" -> ".-.",
-                       "S" -> "...", "T" -> "-", "U" -> "..-", "V" -> "...-", "W" -> ".--", "X" -> "-..-",
-                       "Y" -> "-.--", "Z" -> "--..")
+  @tailrec
+  def fibonacciAccumulator(a: Int, b: Int, i: Int): Int = i match {
+    case 0 => a
+    case i => fibonacciAccumulator(b, a + b, i - 1)
+  }
 
-  def morse(text: String): String = ???
+  def fibonacci(idx: Int): Seq[Int] =
+    (0 to idx).map(fibonacci4Index)
 
+//  @tailrec
+//  def fibonacciListAccumulator(list: List[Int], a: Int, b: Int, i: Int): List[Int] = i match {
+//    case 0 => a :: Nil
+//    case i => fibonacciListAccumulator()
+//  }
 
-  def wordReverse(text: String): String = ???
-
+  lazy val MORSE = Map("A" -> ".-", "B" -> "-...", "C" -> "-.-.", "D" -> "-..", "E" -> ".", "F" -> "..-.",
+    "G" -> "--.", "H" -> "....", "I" -> "..", "J" -> ".---", "K" -> "-.-", "L" -> ".-..",
+    "M" -> "--", "N" -> "-.", "O" -> "---", "P" -> ".--.", "Q" -> "--.-", "R" -> ".-.",
+    "S" -> "...", "T" -> "-", "U" -> "..-", "V" -> "...-", "W" -> ".--", "X" -> "-..-",
+    "Y" -> "-.--", "Z" -> "--..")
+
+  def morse(text: String): String =
+    text
+      .toUpperCase
+      .map(s => MORSE.getOrElse(s.toString, s.toString))
+      .mkString(" ")
+
+
+  def wordReverse(text: String): String = text.foldLeft(("", "")) {
+    case ((text, word), char) if char.isLetter => (text, word + char)
+    case ((text, word), char) => (text + word.headOption.fold("")(c => if (c.isUpper) word.toLowerCase.reverse.capitalize else word.reverse) + char, "")
+  } match {
+    case (text, word) => text + word
+  }
 }

homeworks/homework_6/src/test/scala/Test.scala

@@ -21,7 +21,8 @@ object Test extends TestSuite{
 
     'morse - {
       assert(Exercises.morse("SOS") == "... --- ...")
-      assert(Exercises.morse("Hello world!") == ".... . .-.. .-.. ---   .-- --- .-. .-.. -..!")
+      val actual = Exercises.morse("Hello world!")
+      assert(actual == ".... . .-.. .-.. ---   .-- --- .-. .-.. -..!")
     }
 
     'wordReverse - {