public class DoggieAnimation {
    public static void main(String[] args) {
        // Setup Canvas and Scale
        StdDraw.setCanvasSize(1024, 768);
        StdDraw.setScale(-1024, 1024);

        IntBag bag = null;

        // Add each picture once
        for (int i = 1; i <= 10; i++) {
            bag.add(i);
        }

        // Add my favorite picture many times
        for (int i = 0; i < 10; i++) {
            bag.add(3);
        }

        while (true) {
            // get next picture name
            String pic = "pictures/hopper" + bag.pick() + ".jpg";
            // draw it
            StdDraw.picture(0, 0, pic);
            // pause
            StdDraw.pause(2000);
            System.out.println(pic);
        }
    }
}