The problem has been solved when you are at the mall entrance.

Of course you know how to cross a parking lot. You would probably describe the process as "...keep walking until you reach the entrance."

Let us describe the solution in more detail:

- If you are one step from the mall, take that step and you are done.
- If you are further than one step from the mall, divide the distance into two parts:
- a single step, and
- the remaining distance.

I've described the solution in a recursive style. There are two parts to recursion:

- If the problem is easy, solve it immediately.
- If the problem can't be solved immediately,
divide it into smaller problems, then:
- Solve the smaller problems by applying this procedure to each of them.

The over-all strategy is to find some easily applied action that breaks the problem into smaller pieces. Some of the pieces can be dealt with immediately; others need to be further broken up.