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import UIKit

class ViewController: UIViewController {
    
    @IBOutlet weak var button1: UIButton!
    @IBOutlet weak var button2: UIButton!
    @IBOutlet weak var button3: UIButton!
    @IBOutlet weak var button4: UIButton!
    
    var images = ["image1", "image2", "image3", "image4"]
    var currentImages = [String]()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        randomizeImages()
    }
    
    func randomizeImages() {
        currentImages.removeAll()
        while currentImages.count < 4 {
            let randomIndex = Int(arc4random_uniform(UInt32(images.count)))
            let randomImage = images[randomIndex]
            if !currentImages.contains(randomImage) {
                currentImages.append(randomImage)
            }
        }
        button1.setImage(UIImage(named: currentImages[0]), for: .normal)
        button2.setImage(UIImage(named: currentImages[1]), for: .normal)
        button3.setImage(UIImage(named: currentImages[2]), for: .normal)
        button4.setImage(UIImage(named: currentImages[3]), for: .normal)
    }
    
    @IBAction func buttonTapped(_ sender: UIButton) {
        randomizeImages()
    }
    
}