added final exam

README.md

@@ -21,6 +21,8 @@
     * [Lesson 7 - Advanced typing and infinite lists](#lesson-7---advanced-typing-and-infinite-lists)
     * [Lesson 8 - Futures and parallel collections](#lesson-8---futures-and-parallel-collections)
     * [Lesson 9 - DSLs](#lesson-9---dsls)
+    * [Final preparation](#final-exam-preparation)
+    * [Final](#final-exam)
   * [Assignments](#assignments)
     * [Assignment 1 - Square root](#assignment-1---square-root)
     * [Assignment 2 - Map-reduce](#assignment-2---map-reduce)
@@ -100,6 +102,10 @@
 ### Final exam preparation
 [Files](src/FinalPrep1)
 
+### Final exam
+[Files](src/Final1)
+
+
 ## Assignments
 
 ### Assignment 1 - Square root

src/Final1/Exercise1.scala

@@ -0,0 +1,36 @@
+package exercises
+
+object Exercise1 extends App {
+  def dup[A](r: List[Int], l: List[A]): List[A] = {
+    r.zip(l).flatMap(p => {
+      List.fill(p._1)(p._2)
+    })
+  }
+
+  def removeDup[A](l: List[A]): List[A] = {
+    l match {
+      case head::tail => {
+        head::removeDup(tail.filterNot(e => e == head))
+      }
+      case _ => l
+    }
+  }
+
+  def zip[A, B](first: List[A], second: List[B]): List[(A, B)] = {
+    first match {
+      case head1::tail1 => {
+        second match {
+          case head2::tail2 => {
+            (head1, head2)::zip(tail1, tail2)
+          }
+          case _ => Nil
+        }
+      }
+      case _ => Nil
+    }
+  }
+
+  def zipWith[A, B, C](xs: List[A], ys: List[B])(f: (A, B) => C): List[C] = {
+    zip(xs, ys).map((p: (A, B)) => f(p._1, p._2))
+  }
+}

src/Final1/Exercise2.scala

@@ -0,0 +1,10 @@
+package exercises
+
+object Exercise2 extends App {
+  def gen(charSet: String, length: Int): List[String] = {
+    if (length <= 0) List("")
+    else charSet.toList.flatMap(c => {
+      gen(charSet, length - 1).map(pwd => c.toString + pwd)
+    })
+  }
+}

src/Final1/Exercise3.scala

@@ -0,0 +1,55 @@
+package exercises
+
+object Exercise3 extends App {
+  sealed abstract class Tree {
+    def isMirrorOf(other: Tree): Boolean
+    def isSymmetric(): Boolean
+    def computeDepth(): Int = {
+      this match {
+        case Empty => 1
+        case Node(left, _, right) => 1 + Math.max(left.computeDepth(), right.computeDepth())
+      }
+    }
+    def traverseBreadthFirst(): List[Int] = {
+      val depth: Int = computeDepth()
+      // Construct list of levels
+      def helper(tree: Tree, curDepth: Int = 0): List[List[Int]] = {
+        tree match {
+          // Add empty levels for consistent indices
+          case Empty => List.fill(depth - curDepth)(List.empty[Int])
+          case Node(left, elem, right) => {
+            val leftList: List[List[Int]] = helper(left, curDepth + 1)
+            val rightList: List[List[Int]] = helper(right, curDepth + 1)
+            val res: List[List[Int]] = (0 until depth - curDepth - 1).map(i => {
+              leftList(i) ::: rightList(i)
+            }).toList
+
+            // Add this level
+            List(elem)::res
+          }
+        }
+      }
+      helper(this).flatten
+    }
+  }
+
+  case class Node(left: Tree, elem: Int, right: Tree) extends Tree {
+    def isMirrorOf(other: Tree): Boolean = {
+      other match {
+        case Node(left2, _, right2) => (left isMirrorOf right2) && (right isMirrorOf left2)
+        case _ => false
+      }
+    }
+    def isSymmetric: Boolean = left isMirrorOf right
+  }
+
+  case object Empty extends Tree {
+    def isMirrorOf(other: Tree): Boolean = {
+      other match {
+        case Empty => true
+        case _ => false
+      }
+    }
+    def isSymmetric: Boolean = true
+  }
+}