Type ‘ViewController’ does not conform to protocol ‘UITableViewDataSource’

You should implement all the required methods before the last }, but you have written them outside of the UIViewController. Also, you need to change the func for number of lines.

the suggested edit

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
    @IBOutlet weak var table: UITableView!


    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func tableView(tableView:UITableView!, numberOfRowsInSection section:Int) -> Int
    {
        return 20
    }

    func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell!
    {
        let cell:UITableViewCell=UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: "mycell")
        cell.textLabel.text="row#\(indexPath.row)"
        cell.detailTextLabel.text="subtitle#\(indexPath.row)"

        return cell
    }
}