September 2017 Update

Task/Josephus-problem/Kotlin/josephus-problem.kotlin

@@ -0,0 +1,33 @@
+// version 1.1.3
+
+fun josephus(n: Int, k: Int, m: Int): Pair<List<Int>, List<Int>> {
+    require(k > 0 && m > 0 && n > k && n > m)
+    val killed = mutableListOf<Int>()
+    val survived = MutableList(n) { it }
+    var start = k - 1
+    outer@ while (true) {
+        val end = survived.size - 1
+        var i = start
+        var deleted = 0
+        while (i <= end) {
+            killed.add(survived.removeAt(i - deleted))
+            if (survived.size == m) break@outer
+            deleted++
+            i += k
+        }
+        start = i - end - 1
+    }
+    return Pair(survived, killed)
+}
+
+fun main(args: Array<String>) {
+    val triples = listOf(Triple(5, 2, 1), Triple(41, 3, 1), Triple(41, 3, 3))
+    for (triple in triples) {
+        val(n, k, m) = triple
+        println("Prisoners = $n, Step = $m, Survivors = $m")
+        val (survived, killed)  = josephus(n, k, m)
+        println("Survived   : $survived")
+        println("Kill order : $killed")
+        println()
+    }
+}