Chapter 14

Recursive module
- calls itself
- <=> iteration (looping)


Words:

recursive step			the step in a program or algorithm that contains a
                              recursive call

stopping case			the statement that causes recursion to terminate

activation frame			a device showing the parameters values for each
                              recursive call and its execution

terminating condition		a condition that is true when a recursive module
                              reaches a stopping case

unwinding the recursion		the process of returning from series of recursion
                              calls



When to use:

- one or more stopping cases have simple nonrecursive solutions
- reduce a problem to a smaller problem (closer to the stopping case)
- reduce a problem to a stopping case


How to solve a recursion problem:

- understand the problem
- determine the stopping cases
- determine the recursive steps

IF stoppingcase = True THEN
  solve it
ELSE
  split the problem into simpler cases using recursion


Why recursion instead of iteration:

Some problems are easier to solve with recursion.
Besides, you could have learned recursion first and iteration second.
Then you might wonder why iteration...