One of the oldest computer science Challenges with 46 years of history

Approved by the National Association of Secondary School Principals (NASSP)

Authenticated by the Computer Science Teachers Association

Sponsored by Google, ADOBE and other advanced technology companies

Based on cumulative team scores, top teams are invited to ACSL ALL-Star

4 different levels suitable for students from Grade 3 to 12

Past papers are available for preparation

December, 2023 - August, 2024


ACSL organizes computer programming and computer science contests for K-12 schools, organizations and local groups. The 2023-2024 school year will be our 46th year of continuous operation! Last year, about 8,000 students the United States, Canada, Europe, and Asia participated in the regular season competitions. ACSL is on the approved activities list of the National Association of Secondary School Principals (NASSP). ACSL is also an institutional member of the Computer Science Teachers Association.

Official Website:

Challenge Rules


Chinese & English

  • Round 1 (Top 65% enter Rounds 2-4)
  • Rounds 2-4
  • Round 1: 17 Dec, 2023
  • Round 2: 17 Feb, 2024
  • Round 3: 17 Mar, 2024
  • Round 4: 20 Apr, 2024


Programming Language

Any programming language you are good at


Elementary: students from grade 3 to 6

Junior & Intermediate & Senior: 3 students per team (at least 2 students)

  • Senior Division is geared to high school students with experience in programming, especially those who are taking a Computer Science AP course.
  • Intermediate Division is geared towards senior high school students with computer programming experience, and advanced junior high students.
  • Junior Division is geared to middle school students with no previous experience in programming. No student beyond grade 9 may compete in the Junior Division.
  • Elementary Division is open to students from grades 3 - 6. It consists 5 questions on a computer science topic such as Boolean Algebra and Graph Theory.

Note: Experienced lower grade students can choose higher level contest. For example, primary school students with good programming skills can choose senior, intermediate or junior contest, and junior school students with strong programming skills can choose the senior contest. However, high school students can't choose lower level contests.


Junior & Intermediate & Senior

  • Part 1 (Individual round): 5 multiple choice questions in 30 minutes. 1 point for each question. The full mark is 5 points.
  • Part 2 (Team round): 1 programming question in 2 hours, worth 5 points. (All members of the team are required to answer questions and submit answers)

Elementary Division Only Individual written contest: 5 multiple choice questions in 30 minutes. 1 point for each question. The full mark is 5 points.

  • Individual scores: individual multiple choice question scores + individual programming question scores
  • Team scores: team multiple choice question average scores + team programming question average scores
National Awards

Individual Awards

  • Perfect Score: Get a perfect score in Rounds 2 - 4
  • Individual top Scores: top 20% individuals
  • Excellence Award: Top 55% individuals

Team Awards

  • Gold: Top 10% teams
  • Silver: Top 25% teams
  • Bronze: Top 35% teams
  • Regional Honorable Awards: Regional Top 20% teams

Reward by different levels. Team members who miss one round at most can receive team awards.

All-Star Contest

The winning teams/individuals will be invited to participate in All-Star Contest. The Contest will be held on August, 2024. All the teams will compete in their own division.

The topics that are covered in ACSL Rounds 1-4

Each topic is linked to the page of the ACSL wiki

Division Elementary Junior Intermediate & Senior Division
Round 1 Computer Number System Computer Number System.Recursive Functions.
What Does This Program Do?- Branch
Computer Number System.Recursive Functions.
What Does This Program Do? - Branch
Round 2 Prefix/Infix/Postfix Notation Prefix/Infix/Postfix Notation. Bit-String Flicking.
What Does This Program Do? - Loops
Prefix/Infix/Postfix Notation. Bit-String Flicking.
What Does This Program Do? - LISP.
Round 3 Boolean Algebra Boolean Algebra. Data Structures.
What Does This Program Do? - Arrays
Boolean Algebra. Data Structures.
FSAs and Regular Expressions.
Round 4 Graph Theory Graph Theory. Digital Electronics.
What Does This Program Do? - Strings
Graph Theory. Digital Electronics.
Assembly Language.

*Note: The Short Problems topics are the same in the Intermediate and Senior Divisions.The Senior Division problems are more challenging than those in the Intermediate Division.

All-Star Contest


    August, 2024(TBD)


  • Primary:20 multiple choice questions
  • Junior, Intermediate and Senior: 20 multiple choice questions(written contest),2 Programming problems.

*PS:Subject to the actual number of questions.Primary division only has written contest.

Written Contest

  • Elementary:: 60-minute exam consisting of 12 multiple choice questions.
  • Junior, Intermediate and Senior:60-minute exam consisting of 20 multiple choice questions. Team members need to answer questions independently

Programming Contest

  • Format: 3 students per team (at least 2 students)
  • Content: 2 Programming problems scored with 10 points per question. All members of the team are required to answer questions and submit answers. (3 hours)


    Global Awards(only Individual)
  • Gold:Above the score line set by the organizing committee
  • Sliver:Above the score line set by the organizing committee
  • Bronze:Above the score line set by the organizing committee
    National awards
  • Top Scores: 1st, 2nd and 3rd Place Individuals / Teams
  • Gold: Top 10% Individuals / Teams
  • Silver: Top 20% Individuals / Teams
  • Bronze: Top 35% Individuals / Teams
  • Honorable Award: Top 50% Individuals / Teams


  • Individual scores: Individual written scores + Individual programming scores
  • Team scores: Average team written scores + Average team programming scores
  • If there is a tie, the individual/team with the highest score in multiple choice questions will win; if it is still a tie, the individual/team with the higher programming score will win.
  • PS: Points from Regular Season are not counted in All-Star Contest

Agenda(The schedule is subject to the day of the tournament)

Date Time Session
August 2024(TBD) 08:30-09:00 Zoom Debugging
09:00-12:00 Programming Contest
12:00-13:00 Break
13:00-13:30 Zoom Debugging*
13:30-14:30 Written Contest(multiple choice)*
14:40-17:00 Work Presentation*
17:00-17:30 Closing + Awarding Ceremony*

PS:The schedule is subject to the day of the tournament,Elementary only participate in session marked star(*)。



  • Round 2-4 Deadline: 6 Feb. 2024
  • ALL STAR: August, 2024 (TBD)


  • Candidates should bring their own computer for programming competition.

ASDAN EPQ Scholarship







Noted:The ASDAN Scholarship is only available to Year 10, 11 and 12 students for participating ASDAN Extended Project Qualification(EPQ). EPQ is recommended by the G5 group and many leading universities as a competitive academic experience. Scholarships cannot be exchanged for cash. For further details see:

Exam Centers

Final Exam Centers

Sample Problems


Calculators can not be used on ACSL.
2. programming language

C # / Mono, C11 / gcc, GNU C++11/g++,  Go, Haskell / ghc, Java JDK 11.0.10, Java OpenJDK 8, Javascript / nodeJS, Kotlin, Pascal / fpc, Perl, PHP 7.2, Python 2/CPython, Python 3.10/CPython, Python 3.8/CPython, Python 3/CPython, Ruby, Rust, Visual Basic.

If, for some reason, the student is unable to attend after paying the fee, please contact us. If you apply before the registration deadline, 25% of the registration fee will be deducted as academic materials and service fees. If you apply after the registration deadline, no refund will be given.
Northern Contact
Northern Region:
Beijing、Tianjin、Heilongjiang、Jilin、Liaoning、 Heibei、Inner Mongolia、Shanxi、Shandong
Eastern China Contact
Eastern Region:
Central China Contact
Central Region:
Southern China Contact
Southern Region:
Western China Contact
Western Region:
Central China Contact
Central Region: