2017 Code Golf Challenge
A bit of fun (and possibly frustration!) for 2017...our monthly "code golf puzzle". Enjoy!
The Objective
Each month, find the shortest possible APL expression that evaluates to that month's given numerical targets* without using any of the digits 0-9 or the quote glyph ('). For example, numbers 0-2 can be obtained as follows:
⍴⍬
0
≢#
1
⍴⍬⍬
2
*Numerical targets are the week numbers for that month according to https://weeknumber.co.uk/calendar/england/2017.
The aim of code golf is to use as few characters as possible in each expression.
The Rules
- Expressions must not contain the digits 0-9 or the quote glyph (').
- Expressions must not rely on local conditions, for example, the operating system, the exact date/time or specific input from the user.
- System variables can be used but must be set to the Dyalog default values – this includes ⎕ML and ⎕IO (the defaults for these are both 1)
- Returned values can be scalar integers, one-element integer arrays or character vectors but must not include decimals (even ".0").
- Non-redundant spaces are included in the character count.
- Entries will be rated by the number of characters in the submission.
- Entries for each month will only be accepted in that month. However, a summary of expressions for all months can be submitted in December for entry in the cumulative total part of the game.
If you have any questions or spot any loopholes/ambiguities, please email codegolf@dyalog.com.
Eligibility |
Closing Date |
Prizes |
| Anyone can enter. | Monthly & 31 December 2017 | Be immortalised in our 2017 Hall of Fame! |
Submitting Your Entry
Email your expressions in a text file, Microsoft Excel file or workspace to codegolf@dyalog.com stating the version of Dyalog that you wrote/tested them on (don't forget to include your name).
2017 Hall of Fame
Best scores for monthly submissions (only includes those submitted in that month):
| Month | Goals | Number of Characters Used | Name(s) |
|---|---|---|---|
| January | 1, 2, 3, 4, 5 | 16 | Michele Bellon, Veli-Matti Jantunen, Nick Nikolov |
| February | 6, 7, 8, 9 | 17 | Veli-Matti Jantunen, Nick Nikolov |
| March | 10, 11, 12, 13 | 17 | Veli-Matti Jantunen, Nick Nikolov |
| April | 14, 15, 16, 17 | 21 | Veli-Matti Jantunen, Nick Nikolov |
| May | 18, 19, 20, 21, 22 | 25 | Nick Nikolov |
| June | 23, 24, 25, 26 | 19 | Veli-Matti Jantunen, Nick Nikolov |
| July | 27, 28, 29, 30, 31 | 25 | Veli-Matti Jantunen, Nick Nikolov |
| August | 32, 33, 34, 35 | 23 | Roger Hui, Veli-Matti Jantunen, Nick Nikolov |
| September | 36, 37, 38, 39 | 25 | Veli-Matti Jantunen, Nick Nikolov |
| October | 40, 41, 42, 43, 44 | 33 | Nick Nikolov |
| November | 45, 46, 47, 48 | 25 | Roger Hui, Veli-Matti Jantunen, Nick Nikolov |
| December | 49, 50, 51, 52 | 23 | Veli-Matti Jantunen, Nick Nikolov, Jonas Stensiö |
Cumulative scores for submissions for the entire year:
| Name | Number of Characters Used |
|---|---|
| Nick Nikolov Jonas Stensiö |
269 |
| Veli-Matti Jantunen | 271 |
| Giacomo Manfredi | 290 |
| Roger – Dyalog | 294 |
| Dragana Babić | 314 |
| Zachary Taylor | 315 |
An amalgamation of all the entries showing the expressions that use the fewest characters for each number can be downloaded as a text file. Congratulations to Nick Nikolov and Jonas Stensiö, who both achieved the same character count (269), although neither managed to achieve the amalgamated minimum of 267. Of course, there could be shorter expressions out there...