Data commit

Task/Josephus-problem/Wren/josephus-problem.wren

@@ -0,0 +1,32 @@
+var josephus = Fn.new { |n, k, m|
+    if (k <= 0 || m <= 0 || n <= k || n <= m) Fiber.abort("One or more parameters are invalid.")
+    var killed = []
+    var survived = List.filled(n, 0)
+    for (i in 0...n) survived[i] = i
+    var start = k - 1
+    while (true) {
+        var end = survived.count - 1
+        var i = start
+        var deleted = 0
+        while (i <= end) {
+            killed.add(survived.removeAt(i-deleted))
+            if (survived.count == m) return [survived, killed]
+            deleted = deleted + 1
+            i = i + k
+        }
+        start = i - end - 1
+    }
+    return [survived, killed]
+}
+
+var triples = [ [5, 2, 1], [41, 3, 1], [41, 3, 3] ]
+for (triple in triples) {
+    var n = triple[0]
+    var k = triple[1]
+    var m = triple[2]
+    System.print("Prisoners = %(n), Step = %(m), Survivors = %(m)")
+    var sk = josephus.call(n, k, m)
+    System.print("Survived   : %(sk[0])")
+    System.print("Kill order : %(sk[1])")
+    System.print()
+}