The complete prep tool for ACSL students.

Lessons, quizzes, timed contests, and a code editor: everything you need for all 12 Junior Division topics.

Start learning Try a contest

What's included

Lessons for every topic
Detailed guides covering all 12 Junior Division topics, organized by contest.
Practice quizzes
Test yourself topic-by-topic with instant feedback and explanations.
Contest simulation
Full timed contests matching the real ACSL format.
Built-in code editor
Write and run Python, Java, or C++ directly in the browser.
Progress tracking
Track your quiz scores and contest results over time.
Leaderboards
See how you stack up against other students on each contest.

The 4 contests

Contest 1
  • Computer Number Systems
  • Recursive Functions
  • WDTPD – Branching
Contest 2
  • Prefix/Infix/Postfix
  • Bit-String Flicking
  • WDTPD – Looping
Contest 3
  • Boolean Algebra
  • Data Structures
  • WDTPD – Arrays
Contest 4
  • Graph Theory
  • Digital Electronics
  • WDTPD – Strings