12. Flipping pancakes There are n pancakes all of different sizes that are stacked on top of each other. You are allowed to slip a flipper under one of the pancakes and flip over the whole stack above the flipper. The purpose is to arrange pancakes according to their size with the biggest at the bottom. (You can see a visualization of this puzzle on the Interactive Mathematics Miscellany and Puzzles site [Bog].) Design an algorithm for solving this puzzle.