1 files changed, 29 insertions, 0 deletions
diff --git a/src/solvers/Challenge4.scala b/src/solvers/Challenge4.scala
new file mode 100644
index 0000000..f71f6c0
--- /dev/null
+++ b/src/solvers/Challenge4.scala
@@ -0,0 +1,29 @@
+package ixee.cryptopals.solvers
+
+import scala.io.Source
+import ixee.cryptopals.utils.ByteUtils._
+import ixee.cryptopals.utils.ConversionUtils._
+import ixee.cryptopals.utils.FunctionUtils._
+import ixee.cryptopals.utils._
+
+object Challenge4 {
+  def findSingleCharacterXor(strings: Seq[Seq[Byte]]): (String, Int) = {
+    strings
+      .map(XorDecrypt.findBestSingleByteKey)
+      .zip(strings)
+      .zipWithIndex
+      .map { pair => (pair._1._1, pair._1._2, pair._2) }
+      .filter(_._1 != 0)
+      .map { triplet => (XorDecrypt.decryptToAscii(triplet._2)(triplet._1), triplet._3) }
+      .map { pair => (pair._1, TextScorer.score(pair._1.asBytes), pair._2) }
+      .sortBy(_._2)
+      .map { triplet => (triplet._1, triplet._3) }
+      .head
+  }
+
+  def run(inputFile: String) = {
+    findSingleCharacterXor(
+      Source.fromFile(inputFile).getLines().toSeq.map(hexStr2Bytes(_))
+    )
+  }
+}