June 2018 Update

Task/Twelve-statements/Scala/twelve-statements.scala

@@ -0,0 +1,81 @@
+class LogicPuzzle {
+  val s = new Array[Boolean](13)
+  var count = 0
+
+  def check2: Boolean = {
+    var count = 0
+    for (k <- 7 to 12) if (s(k)) count += 1
+
+    s(2) == (count == 3)
+  }
+
+  def check3: Boolean = {
+    var count = 0
+    for (k <- 2 to 12 by 2) if (s(k)) count += 1
+
+    s(3) == (count == 2)
+  }
+
+  def check4: Boolean = s(4) == (!s(5) || s(6) && s(7))
+
+  def check5: Boolean = s(5) == (!s(2) && !s(3) && !s(4))
+
+  def check6: Boolean = {
+    var count = 0
+    for (k <- 1 to 11 by 2) if (s(k)) count += 1
+    s(6) == (count == 4)
+  }
+
+  def check7: Boolean = s(7) == ((s(2) || s(3)) && !(s(2) && s(3)))
+
+  def check8: Boolean = s(8) == (!s(7) || s(5) && s(6))
+
+  def check9: Boolean = {
+    var count = 0
+    for (k <- 1 to 6) if (s(k)) count += 1
+
+    s(9) == (count == 3)
+  }
+
+  def check10: Boolean = s(10) == (s(11) && s(12))
+
+  def check11: Boolean = {
+    var count = 0
+    for (k <- 7 to 9) if (s(k)) count += 1
+
+    s(11) == (count == 1)
+  }
+
+  def check12: Boolean = {
+    var count = 0
+    for (k <- 1 to 11) if (s(k)) count += 1
+    s(12) == (count == 4)
+  }
+
+  def check(): Unit = {
+    if (check2 && check3 && check4 && check5 && check6 && check7 && check8 && check9 && check10 && check11 && check12) {
+      for (k <- 1 to 12) if (s(k)) print(k + " ")
+      println()
+      count += 1
+    }
+  }
+
+  def recurseAll(k: Int): Unit = {
+    if (k == 13) check()
+    else {
+      s(k) = false
+      recurseAll(k + 1)
+      s(k) = true
+      recurseAll(k + 1)
+    }
+  }
+}
+
+object LogicPuzzle extends App {
+  val p = new LogicPuzzle
+  p.s(1) = true
+  p.recurseAll(2)
+  println()
+  println(s"${p.count} Solutions found.")
+
+}