fix for Swift 3

Author: TheIronBorn

Shuffle/Shuffle.playground/Contents.swift

@@ -3,7 +3,7 @@
 import Foundation
 
 /* Returns a random integer between 0 and n-1. */
-public func random(n: Int) -> Int {
+public func random(_ n: Int) -> Int {
   return Int(arc4random_uniform(UInt32(n)))
 }
 
@@ -12,7 +12,7 @@ public func random(n: Int) -> Int {
 /* Fisher-Yates / Knuth shuffle */
 extension Array {
   public mutating func shuffle() {
-    for i in (count - 1).stride(through: 1, by: -1) {
+    for i in stride(from: count - 1, through: 1, by: -1) {
       let j = random(i + 1)
       if i != j {
         swap(&self[i], &self[j])
@@ -29,8 +29,8 @@ list.shuffle()
 
 
 /* Create a new array of numbers that is already shuffled. */
-public func shuffledArray(n: Int) -> [Int] {
-  var a = [Int](count: n, repeatedValue: 0)
+public func shuffledArray(_ n: Int) -> [Int] {
+  var a = [Int](repeating: 0, count: n)
   for i in 0..<n {
     let j = random(i + 1)
     if i != j {