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Challenges

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Challenges Golf a FRACTRAN interpreter

APL (Dyalog Unicode), 33 bytes {×x←⊃(2⌷⍵)(÷⍨(/⍨)0=|)⍺×1⌷⍵:x∇⍵⋄⍺} Try it online! The first case doesn't work because it gets really big, but the other two do. The input is taken on the left a...

posted 3y ago by user‭  ·  edited 3y ago by user‭

Answer
#2: Post edited by user avatar user‭ · 2021-05-05T16:10:53Z (almost 3 years ago)
  • # [APL (Dyalog Unicode)], 33 bytes
  • <!-- language-all: lang-apl -->
  • {×x←⊃(2⌷⍵)(÷⍨(/⍨)0=|)⍺×1⌷⍵:x∇⍵⋄⍺}
  • [Try it online!][TIO-ko9a95i1]
  • [APL (Dyalog Unicode)]: https://www.dyalog.com/
  • [TIO-ko9a95i1]: https://tio.run/##JYwxbsJAEEV7n@KXtkQUdjfLYiRuwQVAxGsnSEayEVjgCgQhyUp0rmhS5QCJIqX1TeYiZmyaeaM/8/50uXiYF9NFapsmouNlW1cbBr3vfUmff@R@A79mfPuPPIL@eBeQ@68rcT@ONvR2YtLHgeOyaWzbwWtE7uzLzqTzV1sjyf0wS88TMhwggoTgSEF6npGweNIaSvUgBEQLXnpQMF0i20Cx2w8HQmmjFBtmCHbY4pvuvhgG5K6YxEmGl1WWwz7nGfI0xSyxSOavWMfFDQ "APL (Dyalog Unicode) – Try It Online"
  • The first case doesn't work because it gets really big, but the other two do. The input is taken on the left and the fractions are taken as a table on the right.
  • # [APL (Dyalog Unicode)], 33 bytes
  • <!-- language-all: lang-apl -->
  • {×x←⊃(2⌷⍵)(÷⍨(/⍨)0=|)⍺×1⌷⍵:x∇⍵⋄⍺}
  • [Try it online!][TIO-ko9a95i1]
  • [APL (Dyalog Unicode)]: https://www.dyalog.com/
  • [TIO-ko9a95i1]: https://tio.run/##JYwxbsJAEEV7n@KXtkQUdjfLYiRuwQVAxGsnSEayEVjgCgQhyUp0rmhS5QCJIqX1TeYiZmyaeaM/8/50uXiYF9NFapsmouNlW1cbBr3vfUmff@R@A79mfPuPPIL@eBeQ@68rcT@ONvR2YtLHgeOyaWzbwWtE7uzLzqTzV1sjyf0wS88TMhwggoTgSEF6npGweNIaSvUgBEQLXnpQMF0i20Cx2w8HQmmjFBtmCHbY4pvuvhgG5K6YxEmGl1WWwz7nGfI0xSyxSOavWMfFDQ "APL (Dyalog Unicode) – Try It Online"
  • The first case doesn't work because it gets really big, but the other two do. The input is taken on the left and the fractions are taken as a table on the right.
  • ```
  • {×x←⊃(2⌷⍵)(÷⍨(/⍨)0=|)⍺×1⌷⍵:x∇⍵⋄⍺}
  • ⍺× ⍝ n multiplied by
  • 1⌷⍵ ⍝ The first row of the right argument (every p)
  • (2⌷⍵) ⍝ Second row of right arg (all q's)
  • | ⍝ All n×p modulo q
  • 0= ⍝ Check which ones are 0 (rational)
  • ÷⍨ ⍝ Make another vector of 'n×p÷q's
  • /⍨ ⍝ And keep the ones that were rational
  • ⊃ ⍝ Pick the first (0 if empty)
  • x← ⍝ Assign to x
  • × ⍝ Sign of x
  • ⍺ ⍝ If sign is 0, return n
  • x∇⍵ ⍝ Otherwise, call again with x as new n
  • ```
#1: Initial revision by user avatar user‭ · 2021-05-04T00:18:38Z (almost 3 years ago)
# [APL (Dyalog Unicode)], 33 bytes

<!-- language-all: lang-apl -->

    {×x←⊃(2⌷⍵)(÷⍨(/⍨)0=|)⍺×1⌷⍵:x∇⍵⋄⍺}

[Try it online!][TIO-ko9a95i1]

[APL (Dyalog Unicode)]: https://www.dyalog.com/
[TIO-ko9a95i1]: https://tio.run/##JYwxbsJAEEV7n@KXtkQUdjfLYiRuwQVAxGsnSEayEVjgCgQhyUp0rmhS5QCJIqX1TeYiZmyaeaM/8/50uXiYF9NFapsmouNlW1cbBr3vfUmff@R@A79mfPuPPIL@eBeQ@68rcT@ONvR2YtLHgeOyaWzbwWtE7uzLzqTzV1sjyf0wS88TMhwggoTgSEF6npGweNIaSvUgBEQLXnpQMF0i20Cx2w8HQmmjFBtmCHbY4pvuvhgG5K6YxEmGl1WWwz7nGfI0xSyxSOavWMfFDQ "APL (Dyalog Unicode) – Try It Online"

The first case doesn't work because it gets really big, but the other two do. The input is taken on the left and the fractions are taken as a table on the right.