Visualizing recursion

20-minute lesson · module-recursion-04

You are previewing this course as a guest

Read anything and run any exercise you like. It all runs in your own browser, so nothing here is saved: no XP, no progress, and the AI tutor needs an account. Sign in and your work starts counting.

Sign in

Visualizing recursion

20-minute lesson · module-recursion-04

  • Draw the call tree of a recursive function such as power or Fibonacci.
  • Distinguish linear recursion (one call) from tree recursion (two calls).
  • Explain why naive Fibonacci repeats work and grows explosively.
  • Trace the order in which recursive calls are made and returned.

Source attribution

Status: adapted

How to Think Like a Computer Scientist: Interactive Edition source · Recursion / Visualizing Recursion

Adaptation notes. Reading rewritten in our voice. Instead of the chapter's turtle drawings (which need a graphics canvas), we visualize recursion through the CALL STRUCTURE of power (linear) and Fibonacci (tree), with a codelens that prints the calls as they happen. Hidden tests check both functions.

License notes. Original chapter is GNU FDL 1.3 (Brad Miller, David Ranum, and the upstream Elkner/Downey/Meyers text). No verbatim text reproduced.