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Add anagram exercise (#40)
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* Add anagram exercise

* Set difficulty to 3
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ageron authored Aug 27, 2024
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8 changes: 8 additions & 0 deletions config.json
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"practices": [],
"prerequisites": [],
"difficulty": 2
},
{
"slug": "anagram",
"name": "Anagram",
"uuid": "40942be8-7c32-4da3-acff-a2365087cd5d",
"practices": [],
"prerequisites": [],
"difficulty": 3
}
]
},
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13 changes: 13 additions & 0 deletions exercises/practice/anagram/.docs/instructions.md
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# Instructions

Your task is to, given a target word and a set of candidate words, to find the subset of the candidates that are anagrams of the target.

An anagram is a rearrangement of letters to form a new word: for example `"owns"` is an anagram of `"snow"`.
A word is _not_ its own anagram: for example, `"stop"` is not an anagram of `"stop"`.

The target and candidates are words of one or more ASCII alphabetic characters (`A`-`Z` and `a`-`z`).
Lowercase and uppercase characters are equivalent: for example, `"PoTS"` is an anagram of `"sTOp"`, but `StoP` is not an anagram of `sTOp`.
The anagram set is the subset of the candidate set that are anagrams of the target (in any order).
Words in the anagram set should have the same letter case as in the candidate set.

Given the target `"stone"` and candidates `"stone"`, `"tones"`, `"banana"`, `"tons"`, `"notes"`, `"Seton"`, the anagram set is `"tones"`, `"notes"`, `"Seton"`.
12 changes: 12 additions & 0 deletions exercises/practice/anagram/.docs/introduction.md
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# Introduction

At a garage sale, you find a lovely vintage typewriter at a bargain price!
Excitedly, you rush home, insert a sheet of paper, and start typing away.
However, your excitement wanes when you examine the output: all words are garbled!
For example, it prints "stop" instead of "post" and "least" instead of "stale."
Carefully, you try again, but now it prints "spot" and "slate."
After some experimentation, you find there is a random delay before each letter is printed, which messes up the order.
You now understand why they sold it for so little money!

You realize this quirk allows you to generate anagrams, which are words formed by rearranging the letters of another word.
Pleased with your finding, you spend the rest of the day generating hundreds of anagrams.
46 changes: 46 additions & 0 deletions exercises/practice/anagram/.meta/Example.roc
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module [findAnagrams]

import unicode.Grapheme

toUpper = \text ->
text
|> Str.toUtf8
|> List.map \c ->
if c >= 'a' && c <= 'z' then
c - 'a' + 'A'
else
c
|> Str.fromUtf8
|> Result.withDefault "Unreachable"

compareGraphemes = \g1, g2 ->
s1 = g1 |> Str.toUtf8
s2 = g2 |> Str.toUtf8
cmp =
List.map2 s1 s2 \b1, b2 -> (b1, b2)
|> List.walkUntil EQ \_, (b1, b2) ->
if b1 == b2 then
Continue EQ
else if b1 < b2 then
Break LT
else
Break GT
if cmp == EQ then
Num.compare (List.len s1) (List.len s2)
else
cmp

sortedGraphemes = \word ->
graphemes = word |> Grapheme.split?
graphemes |> List.sortWith compareGraphemes |> Ok

isAnagramOf = \word1, word2 ->
sorted1 = word1 |> toUpper |> sortedGraphemes?
sorted2 = word2 |> toUpper |> sortedGraphemes?
Ok (sorted1 == sorted2)

findAnagrams = \subject, candidates ->
candidates
|> List.dropIf \word -> toUpper word == toUpper subject
|> List.keepIf \word ->
word |> isAnagramOf subject |> Result.withDefault Bool.false
19 changes: 19 additions & 0 deletions exercises/practice/anagram/.meta/config.json
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{
"authors": [
"ageron"
],
"files": {
"solution": [
"Anagram.roc"
],
"test": [
"anagram-test.roc"
],
"example": [
".meta/Example.roc"
]
},
"blurb": "Given a word and a list of possible anagrams, select the correct sublist.",
"source": "Inspired by the Extreme Startup game",
"source_url": "https://github.com/rchatley/extreme_startup"
}
13 changes: 13 additions & 0 deletions exercises/practice/anagram/.meta/template.j2
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{%- import "generator_macros.j2" as macros with context -%}
{{ macros.canonical_ref() }}
{{ macros.header(imports=["unicode"]) }}

import {{ exercise | to_pascal }} exposing [{{ cases[0]["property"] | to_camel }}]

{% for case in cases -%}
# {{ case["description"] }}
expect
result = {{ case["property"] | to_camel }} {{ case["input"]["subject"] | to_roc }} {{ case["input"]["candidates"] | to_roc }}
result == {{ case["expected"] | to_roc }}

{% endfor %}
87 changes: 87 additions & 0 deletions exercises/practice/anagram/.meta/tests.toml
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# 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.

[dd40c4d2-3c8b-44e5-992a-f42b393ec373]
description = "no matches"

[b3cca662-f50a-489e-ae10-ab8290a09bdc]
description = "detects two anagrams"
include = false

[03eb9bbe-8906-4ea0-84fa-ffe711b52c8b]
description = "detects two anagrams"
reimplements = "b3cca662-f50a-489e-ae10-ab8290a09bdc"

[a27558ee-9ba0-4552-96b1-ecf665b06556]
description = "does not detect anagram subsets"

[64cd4584-fc15-4781-b633-3d814c4941a4]
description = "detects anagram"

[99c91beb-838f-4ccd-b123-935139917283]
description = "detects three anagrams"

[78487770-e258-4e1f-a646-8ece10950d90]
description = "detects multiple anagrams with different case"

[1d0ab8aa-362f-49b7-9902-3d0c668d557b]
description = "does not detect non-anagrams with identical checksum"

[9e632c0b-c0b1-4804-8cc1-e295dea6d8a8]
description = "detects anagrams case-insensitively"

[b248e49f-0905-48d2-9c8d-bd02d8c3e392]
description = "detects anagrams using case-insensitive subject"

[f367325c-78ec-411c-be76-e79047f4bd54]
description = "detects anagrams using case-insensitive possible matches"

[7cc195ad-e3c7-44ee-9fd2-d3c344806a2c]
description = "does not detect an anagram if the original word is repeated"
include = false

[630abb71-a94e-4715-8395-179ec1df9f91]
description = "does not detect an anagram if the original word is repeated"
reimplements = "7cc195ad-e3c7-44ee-9fd2-d3c344806a2c"

[9878a1c9-d6ea-4235-ae51-3ea2befd6842]
description = "anagrams must use all letters exactly once"

[85757361-4535-45fd-ac0e-3810d40debc1]
description = "words are not anagrams of themselves (case-insensitive)"
include = false

[68934ed0-010b-4ef9-857a-20c9012d1ebf]
description = "words are not anagrams of themselves"
reimplements = "85757361-4535-45fd-ac0e-3810d40debc1"

[589384f3-4c8a-4e7d-9edc-51c3e5f0c90e]
description = "words are not anagrams of themselves even if letter case is partially different"
reimplements = "85757361-4535-45fd-ac0e-3810d40debc1"

[ba53e423-7e02-41ee-9ae2-71f91e6d18e6]
description = "words are not anagrams of themselves even if letter case is completely different"
reimplements = "85757361-4535-45fd-ac0e-3810d40debc1"

[a0705568-628c-4b55-9798-82e4acde51ca]
description = "words other than themselves can be anagrams"
include = false

[33d3f67e-fbb9-49d3-a90e-0beb00861da7]
description = "words other than themselves can be anagrams"
reimplements = "a0705568-628c-4b55-9798-82e4acde51ca"

[a6854f66-eec1-4afd-a137-62ef2870c051]
description = "handles case of greek letters"
include = false

[fd3509e5-e3ba-409d-ac3d-a9ac84d13296]
description = "different characters may have the same bytes"
8 changes: 8 additions & 0 deletions exercises/practice/anagram/Anagram.roc
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module [findAnagrams]

findAnagrams = \subject, candidates ->
crash "Please implement the 'findAnagrams' function"

# HINT: we have added the `unicode` package to the app's header in
# anagram-test.roc, so you can use it here if you need to.
# For example, you could import unicode.Grapheme, just sayin'.
100 changes: 100 additions & 0 deletions exercises/practice/anagram/anagram-test.roc
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# These tests are auto-generated with test data from:
# https://github.com/exercism/problem-specifications/tree/main/exercises/anagram/canonical-data.json
# File last updated on 2024-08-27
app [main] {
pf: platform "https://github.com/roc-lang/basic-cli/releases/download/0.14.0/dC5ceT962N_4jmoyoffVdphJ_4GlW3YMhAPyGPr-nU0.tar.br",
unicode: "https://github.com/roc-lang/unicode/releases/download/0.1.2/vH5iqn04ShmqP-pNemgF773f86COePSqMWHzVGrAKNo.tar.br",
}

import pf.Task exposing [Task]

main =
Task.ok {}

import Anagram exposing [findAnagrams]

# no matches
expect
result = findAnagrams "diaper" ["hello", "world", "zombies", "pants"]
result == []

# detects two anagrams
expect
result = findAnagrams "solemn" ["lemons", "cherry", "melons"]
result == ["lemons", "melons"]

# does not detect anagram subsets
expect
result = findAnagrams "good" ["dog", "goody"]
result == []

# detects anagram
expect
result = findAnagrams "listen" ["enlists", "google", "inlets", "banana"]
result == ["inlets"]

# detects three anagrams
expect
result = findAnagrams "allergy" ["gallery", "ballerina", "regally", "clergy", "largely", "leading"]
result == ["gallery", "regally", "largely"]

# detects multiple anagrams with different case
expect
result = findAnagrams "nose" ["Eons", "ONES"]
result == ["Eons", "ONES"]

# does not detect non-anagrams with identical checksum
expect
result = findAnagrams "mass" ["last"]
result == []

# detects anagrams case-insensitively
expect
result = findAnagrams "Orchestra" ["cashregister", "Carthorse", "radishes"]
result == ["Carthorse"]

# detects anagrams using case-insensitive subject
expect
result = findAnagrams "Orchestra" ["cashregister", "carthorse", "radishes"]
result == ["carthorse"]

# detects anagrams using case-insensitive possible matches
expect
result = findAnagrams "orchestra" ["cashregister", "Carthorse", "radishes"]
result == ["Carthorse"]

# does not detect an anagram if the original word is repeated
expect
result = findAnagrams "go" ["goGoGO"]
result == []

# anagrams must use all letters exactly once
expect
result = findAnagrams "tapper" ["patter"]
result == []

# words are not anagrams of themselves
expect
result = findAnagrams "BANANA" ["BANANA"]
result == []

# words are not anagrams of themselves even if letter case is partially different
expect
result = findAnagrams "BANANA" ["Banana"]
result == []

# words are not anagrams of themselves even if letter case is completely different
expect
result = findAnagrams "BANANA" ["banana"]
result == []

# words other than themselves can be anagrams
expect
result = findAnagrams "LISTEN" ["LISTEN", "Silent"]
result == ["Silent"]

# different characters may have the same bytes
expect
result = findAnagrams "a⬂" ["€a"]
result == []

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