Winning the APL Programming Contest – General Computing Category

#Dyalog’16 – Vibeke Ulmann

Today we had the first of the 3 grand prize winner presentations.

Joshua David is 19 years old and is in his second year studying Computer Science at the University of Scranton. He is also taking a minor in Philosophy – and he’s been an intern with Carlisle Group where the CEO Paul Mansour introduced him to the APL programming contest.

See Joshua’s profile here:

Joshua willingly admitted that he had knowledge of the Dyalog APL language coming into the contest and he actually also entered the contest last year – where he came second. Joshua said that for this year’s contest, it was not so much a case of having to learn the APL language – but more a case of coming up with very elegant solutions in APL.

The problems presented in Phase 1 he found relatively easy to walk through. 10 problems each had to be solved – and the solution to each problem had to be presented in one single line of APL code.

However, Joshua was quick to say that Phase 2 presented him with problems that got increasing harder and harder to solve. In one case he almost had to reverse engineer, how he arrived at the solution, in order to quantify the step by step process of reducing a database of pharmaceutical products to match inputs from prescriptions with typos, dosage, and other irrelevant information.

He then showed us how he solved the 3 problems in Phase 2 and told us how long it approximately took him to arrive at the solutions:
• The Teeko Game Problem  – approx. 2 hours
• The ChiSquare test of independence – approx. 2 hours
• The MatchDrugs problem – approx. 2 days

Suffice it to say – his solutions were very elegantly presented.

The presentation was streamed live on and will also be available on Dyalog’s YouTube channel at a later date, post Dyalog’16.

NOTE: The two other winner presentations from this year’s APL Programming Contest will also be streamed live – and I will blog about them too.

Check out:

  • Marinus Oosters – will present the winning solution in the Bioinformatics category Tuesday 11 Oct 11:45 -12:45 (UK time)
  • Zack Batik – will present the winning solution in the Finance category  Wednesday 12 Oct 13:15 -13:45 (UK time)

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