From 91a7bd8290033ca5bbef57c05a832eaea5c78139 Mon Sep 17 00:00:00 2001 From: Erik Schierboom Date: Sat, 23 Nov 2024 11:59:23 +0100 Subject: [PATCH] Add `run-length-encoding` exercise (#71) --- config.json | 8 +++ .../run-length-encoding/.docs/instructions.md | 20 ++++++++ .../run-length-encoding/.meta/config.json | 19 +++++++ .../run-length-encoding/.meta/example.ua | 8 +++ .../run-length-encoding/.meta/tests.toml | 49 +++++++++++++++++++ .../run-length-encoding.ua | 7 +++ .../practice/run-length-encoding/tests.ua | 40 +++++++++++++++ 7 files changed, 151 insertions(+) create mode 100644 exercises/practice/run-length-encoding/.docs/instructions.md create mode 100644 exercises/practice/run-length-encoding/.meta/config.json create mode 100644 exercises/practice/run-length-encoding/.meta/example.ua create mode 100644 exercises/practice/run-length-encoding/.meta/tests.toml create mode 100644 exercises/practice/run-length-encoding/run-length-encoding.ua create mode 100644 exercises/practice/run-length-encoding/tests.ua diff --git a/config.json b/config.json index 8b1cbcb..3ff8e47 100644 --- a/config.json +++ b/config.json @@ -306,6 +306,14 @@ "prerequisites": [], "difficulty": 2 }, + { + "slug": "run-length-encoding", + "name": "Run-Length Encoding", + "uuid": "d83ea09c-39f9-4e00-9a74-3f1d3be262ac", + "practices": [], + "prerequisites": [], + "difficulty": 7 + }, { "slug": "space-age", "name": "Space Age", diff --git a/exercises/practice/run-length-encoding/.docs/instructions.md b/exercises/practice/run-length-encoding/.docs/instructions.md new file mode 100644 index 0000000..fc8ce05 --- /dev/null +++ b/exercises/practice/run-length-encoding/.docs/instructions.md @@ -0,0 +1,20 @@ +# Instructions + +Implement run-length encoding and decoding. + +Run-length encoding (RLE) is a simple form of data compression, where runs (consecutive data elements) are replaced by just one data value and count. + +For example we can represent the original 53 characters with only 13. + +```text +"WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWB" -> "12WB12W3B24WB" +``` + +RLE allows the original data to be perfectly reconstructed from the compressed data, which makes it a lossless data compression. + +```text +"AABCCCDEEEE" -> "2AB3CD4E" -> "AABCCCDEEEE" +``` + +For simplicity, you can assume that the unencoded string will only contain the letters A through Z (either lower or upper case) and whitespace. +This way data to be encoded will never contain any numbers and numbers inside data to be decoded always represent the count for the following character. diff --git a/exercises/practice/run-length-encoding/.meta/config.json b/exercises/practice/run-length-encoding/.meta/config.json new file mode 100644 index 0000000..95c9a03 --- /dev/null +++ b/exercises/practice/run-length-encoding/.meta/config.json @@ -0,0 +1,19 @@ +{ + "authors": [ + "erikschierboom" + ], + "files": { + "solution": [ + "run-length-encoding.ua" + ], + "test": [ + "tests.ua" + ], + "example": [ + ".meta/example.ua" + ] + }, + "blurb": "Implement run-length encoding and decoding.", + "source": "Wikipedia", + "source_url": "https://en.wikipedia.org/wiki/Run-length_encoding" +} diff --git a/exercises/practice/run-length-encoding/.meta/example.ua b/exercises/practice/run-length-encoding/.meta/example.ua new file mode 100644 index 0000000..d82c2e3 --- /dev/null +++ b/exercises/practice/run-length-encoding/.meta/example.ua @@ -0,0 +1,8 @@ +EncodeRun ← |1 ⊂⊃(⨬(""|°⋕)>1.⧻|⊢) +EncodeRuns ← |1 ⍜(-@\0|⊜□.) +Encode ← |1 /$"__" ⍚(EncodeRun) EncodeRuns + +IsDigit ← |1 ×⊃(≥@0|≤@9) +UpdateRun ← |2 + ⊙(×10) -@0 +DecodeRun ← 0 ⊂: ▽ ⨬(1|∘)±. : +Decode ← |1 ◌ ∧(⨬(DecodeRun|UpdateRun) IsDigit.) ⊙(0 "") diff --git a/exercises/practice/run-length-encoding/.meta/tests.toml b/exercises/practice/run-length-encoding/.meta/tests.toml new file mode 100644 index 0000000..7bdb808 --- /dev/null +++ b/exercises/practice/run-length-encoding/.meta/tests.toml @@ -0,0 +1,49 @@ +# This is an auto-generated file. +# +# Regenerating this file via `configlet sync` will: +# - Recreate every `description` key/value pair +# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications +# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion) +# - Preserve any other key/value pair +# +# As user-added comments (using the # character) will be removed when this file +# is regenerated, comments can be added via a `comment` key. + +[ad53b61b-6ffc-422f-81a6-61f7df92a231] +description = "run-length encode a string -> empty string" + +[52012823-b7e6-4277-893c-5b96d42f82de] +description = "run-length encode a string -> single characters only are encoded without count" + +[b7868492-7e3a-415f-8da3-d88f51f80409] +description = "run-length encode a string -> string with no single characters" + +[859b822b-6e9f-44d6-9c46-6091ee6ae358] +description = "run-length encode a string -> single characters mixed with repeated characters" + +[1b34de62-e152-47be-bc88-469746df63b3] +description = "run-length encode a string -> multiple whitespace mixed in string" + +[abf176e2-3fbd-40ad-bb2f-2dd6d4df721a] +description = "run-length encode a string -> lowercase characters" + +[7ec5c390-f03c-4acf-ac29-5f65861cdeb5] +description = "run-length decode a string -> empty string" + +[ad23f455-1ac2-4b0e-87d0-b85b10696098] +description = "run-length decode a string -> single characters only" + +[21e37583-5a20-4a0e-826c-3dee2c375f54] +description = "run-length decode a string -> string with no single characters" + +[1389ad09-c3a8-4813-9324-99363fba429c] +description = "run-length decode a string -> single characters with repeated characters" + +[3f8e3c51-6aca-4670-b86c-a213bf4706b0] +description = "run-length decode a string -> multiple whitespace mixed in string" + +[29f721de-9aad-435f-ba37-7662df4fb551] +description = "run-length decode a string -> lowercase string" + +[2a762efd-8695-4e04-b0d6-9736899fbc16] +description = "encode and then decode -> encode followed by decode gives original string" diff --git a/exercises/practice/run-length-encoding/run-length-encoding.ua b/exercises/practice/run-length-encoding/run-length-encoding.ua new file mode 100644 index 0000000..614c38e --- /dev/null +++ b/exercises/practice/run-length-encoding/run-length-encoding.ua @@ -0,0 +1,7 @@ +# Encode a string using run-length encoding +# Ciphertext ? Plaintext +Encode ← |1 ⊙(⍤ "Please implement Encode" 0) + +# Decode a string encoded with run-length encoding +# Plaintext ? Ciphertext +Decode ← |1 ⊙(⍤ "Please implement Decode" 0) diff --git a/exercises/practice/run-length-encoding/tests.ua b/exercises/practice/run-length-encoding/tests.ua new file mode 100644 index 0000000..5c8b6bd --- /dev/null +++ b/exercises/practice/run-length-encoding/tests.ua @@ -0,0 +1,40 @@ +~ "run-length-encoding.ua" ~ Decode Encode + +# Encode empty string +⍤⤙≍ "" Encode "" + +# Encode single characters only are encoded without count +⍤⤙≍ "XYZ" Encode "XYZ" + +# Encode string with no single characters +⍤⤙≍ "2A3B4C" Encode "AABBBCCCC" + +# Encode single characters mixed with repeated characters +⍤⤙≍ "12WB12W3B24WB" Encode "WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWB" + +# Encode multiple whitespace mixed in string +⍤⤙≍ "2 hs2q q2w2 " Encode " hsqq qww " + +# Encode lowercase characters +⍤⤙≍ "2a3b4c" Encode "aabbbcccc" + +# Decode empty string +⍤⤙≍ "" Decode "" + +# Decode single characters only +⍤⤙≍ "XYZ" Decode "XYZ" + +# Decode string with no single characters +⍤⤙≍ "AABBBCCCC" Decode "2A3B4C" + +# Decode single characters with repeated characters +⍤⤙≍ "WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWB" Decode "12WB12W3B24WB" + +# Decode multiple whitespace mixed in string +⍤⤙≍ " hsqq qww " Decode "2 hs2q q2w2 " + +# Decode lowercase string +⍤⤙≍ "aabbbcccc" Decode "2a3b4c" + +# Encode followed by decode gives original string +⍤⤙≍ "zzz ZZ zZ" Decode Encode "zzz ZZ zZ"