Array+Shuffle.swift

// Fisher–Yates Array shuffle
extension Array {
    func shuffledArray() -> Array {
        var arr = self
        
        for i in 0..<count {
            print(count - i)
            let j = i + Int(arc4random_uniform(UInt32(count - i)))
            let tmp = arr[i]
            arr[i] = arr[j]
            arr[j] = tmp
        }
        
        return arr
    }
}