Add Coding with squared strings

Kata: 56fcc393c5957c666900024d

Readme.md

@@ -41,6 +41,7 @@ Stores my solutions to kata problems listed on [Codewars](https://www.codewars.c
 [The Hashtag Generator](https://www.codewars.com/kata/52449b062fb80683ec000024),
 [Human Readable Time](https://www.codewars.com/kata/52685f7382004e774f0001f7),
 [Last Digit of a Large Number](./src/main/scala/sierikov/codewars/kyu5/LastDigitOfLargeNumber.scala),
+[Coding with Squared String](./src/main/scala/sierikov/codewars/kyu5/CodingWithSquaredStrings.scala)
 
 ### 6 kuy
 

src/main/scala/sierikov/codewars/kyu5/CodingWithSquaredStrings.scala

@@ -0,0 +1,30 @@
+package sierikov.codewars.kyu5
+
+/**
+ * Kata: https://www.codewars.com/kata/56fcc393c5957c666900024d
+ */
+object CodingWithSquaredStrings {
+
+  def code(s: String): String = {
+    val n = math.sqrt(s.length).ceil.toInt
+    val square = n * n
+    val str = s + "\u000b" * (square - s.length)
+
+    rotateMatrixClockwise(str.toList.grouped(n).toList).map(_.mkString).mkString("\n")
+  }
+
+  def decode(s: String): String = {
+    val m = rotateMatrixAnticlockwise(s.split("\n").map(_.split("").toList).toList)
+    m.flatten.mkString.takeWhile(x => x != '\u000b')
+  }
+
+  private def rotateMatrixClockwise[A](m: List[List[A]]): List[List[A]] = {
+    if (m.isEmpty || m.head.isEmpty) return m
+    m.head.indices.map { i => m.reverseIterator.map(_(i)).toList }.toList
+  }
+
+  private def rotateMatrixAnticlockwise[A](m: List[List[A]]): List[List[A]] = {
+    if (m.isEmpty || m.head.isEmpty) return m
+    rotateMatrixClockwise(m.map(_.reverse)).map(_.reverse)
+  }
+}

src/test/scala/sierikov/codewars/kyu5/CodingWithSquaredStringsTest.scala

@@ -0,0 +1,35 @@
+package sierikov.codewars.kyu5
+
+import org.scalatest.flatspec.AnyFlatSpec
+import sierikov.codewars.kyu5.CodingWithSquaredStrings.*
+
+class CodingWithSquaredStringsTest extends AnyFlatSpec {
+
+  val data = "What do you remember? When I looked at his streaky glasses, I wanted " +
+    "to leave him. And before that? He stole those cherries for me at midnight. We were walking " +
+    "in the rain and I loved him. And before that? I saw him coming " +
+    "toward me that time at the picnic, edgy, foreign."
+
+  val dataEncoded =
+    "\u000bctg?.nadr d gdbW\n\u000b,i    lnis tl eh\n\u000b mtIAakietboaara\n\u000beeo nnigsoe st?t\n\u000bd wsddnh lfls   \n\u000bgaaa  gtfeoeehWd\n" +
+      "\u000bytrwbI .o rasiho\n\u000b, d e i rtev,se \n\u000b t hflnW h e  ny\n\u000bfhmioo emot Is o\n\u000boeemrvt eshh tIu\n\u000br   eehw eaiwr  \n" +
+      "\u000beptc deea tmaelr\n\u000biihot  rtc?.naoe\n\u000bgcamhhre h  tkom\n\u000bnntiaia meHAeyke\n\u000b.i ntmiwirend em"
+
+  it should "pass basic tests code" in {
+    testing(code(data), dataEncoded)
+
+  }
+  it should "pass basic tests decode" in {
+    testing(decode(dataEncoded), data)
+  }
+
+  private def testing(actual: String, expect: String): Unit = {
+    println("Actual: " + actual)
+    println("\nExpect: " + expect)
+    println("-")
+    assertResult(expect) {
+      actual
+    }
+  }
+
+}