Lighter or heavier? You have n > 2 identical-looking coins and a two-pan balance scal...

Lighter or heavier? You have n > 2 identical-looking coins and a two-pan balance scale with no weights. One of the coins is a fake, but you do not know whether it is lighter or heavier than the genuine coins, which all weigh the same. Design a algorithm to determine whether the fake coin is lighter or heavier than the others.