Big O Race Sets - Timed Complexity Practice

Race a curated set of complexity problems against the clock or against a friend's time.

How it works

Pick a set - Sprint, Classic 7, Circuit, Heavy Day, or Marathon - and solve every problem back-to-back as fast as you can. Each set is a fixed sequence so two runs are directly comparable. Share your time as a URL; the recipient runs the same problems and races your ghost.

Sets

  • Sprint - short and punchy, easy warmup
  • Classic 7 - seven canonical interview shapes
  • Circuit - mixed difficulty, balanced topics
  • Heavy Day - harder problems, longer runs
  • Marathon - the full grind

Practice mode · Daily problem