Data commit

Task/100-prisoners/Scala/100-prisoners.scala

@@ -0,0 +1,60 @@
+import scala.util.Random
+import scala.util.control.Breaks._
+
+object Main {
+  def playOptimal(n: Int): Boolean = {
+    val secretList = Random.shuffle((0 until n).toBuffer)
+
+    for (i <- secretList.indices) {
+      var prev = i
+      breakable {
+        for (_ <- 0 until secretList.size / 2) {
+          if (secretList(prev) == i) {
+            break()
+          }
+          prev = secretList(prev)
+        }
+        return false
+      }
+    }
+
+    true
+  }
+
+  def playRandom(n: Int): Boolean = {
+    val secretList = Random.shuffle((0 until n).toBuffer)
+
+    for (i <- secretList.indices) {
+      val trialList = Random.shuffle((0 until n).toBuffer)
+
+      breakable {
+        for (j <- 0 until trialList.size / 2) {
+          if (trialList(j) == i) {
+            break()
+          }
+        }
+        return false
+      }
+    }
+
+    true
+  }
+
+  def exec(n: Int, p: Int, play: Int => Boolean): Double = {
+    var succ = 0.0
+    for (_ <- 0 until n) {
+      if (play(p)) {
+        succ += 1
+      }
+    }
+    (succ * 100.0) / n
+  }
+
+  def main(args: Array[String]): Unit = {
+    val n = 100000
+    val p = 100
+    printf("# of executions: %,d\n", n)
+    printf("Optimal play success rate: %f%%\n", exec(n, p, playOptimal))
+    printf("Random play success rate: %f%%\n", exec(n, p, playRandom))
+  }
+}