CHAPTER 90 — Introduction to Recursion

This chapter introduces recursion. Previous chapters have discussed the fundamental control structures of sequence, alternation (if-else), and iteration (while). Recursion is another control structure. Sometimes problems are stated in a recursive fashion, and a program that solves the problem is most easily written using recursion.

Chapter Topics:

• Two Parts to Recursion:
  • If the problem is easy, solve it immediately.
  • If the problem can't be solved immediately, divide it into easier problems, then recursively solve the easier problems.
• Examples of Recursion:
  • Walking a Distance
  • Smashing a Rock
  • Dividing a Line
  • Drawing a Snowflake

Forget programming for a while. Think about a real-world problem that does not involve computers: