In the previous sections we looked at some problems that are relatively easy to solve and some graphically interesting problems that can help us gain a mental model of what is happening in a recursive algorithm. In this section we will look at some problems that are really difficult to solve using an iterative programming style but are very elegant and easy to solve using recursion. We will finish up by looking at a deceptive problem that at first looks like it has an elegant recursive solution but in fact does not.