If a bar magnet does not have poles written on it, then how will you identify the poles of the magnet?

You are given a few magnets of different shapes as shown in the figure below. If you bring these magnets near a heap of iron filings, where will the maximum filings get attracted? Show in the diagram.

There are two magnets as shown in the figure below. Write what (attraction/ repulsion) will you observe in each case?