diff --git a/config.json b/config.json index af083ca..a872391 100644 --- a/config.json +++ b/config.json @@ -714,6 +714,14 @@ "prerequisites": [], "difficulty": 8 }, + { + "slug": "change", + "name": "Change", + "uuid": "58e7ebd6-e458-4715-bd05-ba6a35ba0573", + "practices": [], + "prerequisites": [], + "difficulty": 8 + }, { "slug": "run-length-encoding", "name": "Run-Length Encoding", diff --git a/exercises/practice/change/.docs/instructions.md b/exercises/practice/change/.docs/instructions.md new file mode 100644 index 0000000..5887f4c --- /dev/null +++ b/exercises/practice/change/.docs/instructions.md @@ -0,0 +1,8 @@ +# Instructions + +Determine the fewest number of coins to give a customer so that the sum of their values equals the correct amount of change. + +## Examples + +- An amount of 15 with available coin values [1, 5, 10, 25, 100] should return one coin of value 5 and one coin of value 10, or [5, 10]. +- An amount of 40 with available coin values [1, 5, 10, 25, 100] should return one coin of value 5, one coin of value 10, and one coin of value 25, or [5, 10, 25]. diff --git a/exercises/practice/change/.docs/introduction.md b/exercises/practice/change/.docs/introduction.md new file mode 100644 index 0000000..b4f8308 --- /dev/null +++ b/exercises/practice/change/.docs/introduction.md @@ -0,0 +1,26 @@ +# Introduction + +In the mystical village of Coinholt, you stand behind the counter of your bakery, arranging a fresh batch of pastries. +The door creaks open, and in walks Denara, a skilled merchant with a keen eye for quality goods. +After a quick meal, she slides a shimmering coin across the counter, representing a value of 100 units. + +You smile, taking the coin, and glance at the total cost of the meal: 88 units. +That means you need to return 12 units in change. + +Denara holds out her hand expectantly. +"Just give me the fewest coins," she says with a smile. +"My pouch is already full, and I don't want to risk losing them on the road." + +You know you have a few options. +"We have Lumis (worth 10 units), Viras (worth 5 units), and Zenth (worth 2 units) available for change." + +You quickly calculate the possibilities in your head: + +- one Lumis (1 × 10 units) + one Zenth (1 × 2 units) = 2 coins total +- two Viras (2 × 5 units) + one Zenth (1 × 2 units) = 3 coins total +- six Zenth (6 × 2 units) = 6 coins total + +"The best choice is two coins: one Lumis and one Zenth," you say, handing her the change. + +Denara smiles, clearly impressed. +"As always, you've got it right." diff --git a/exercises/practice/change/.meta/config.json b/exercises/practice/change/.meta/config.json new file mode 100644 index 0000000..1477c93 --- /dev/null +++ b/exercises/practice/change/.meta/config.json @@ -0,0 +1,19 @@ +{ + "authors": [ + "erikschierboom" + ], + "files": { + "solution": [ + "change.ua" + ], + "test": [ + "tests.ua" + ], + "example": [ + ".meta/example.ua" + ] + }, + "blurb": "Correctly determine change to be given using the least number of coins.", + "source": "Software Craftsmanship - Coin Change Kata", + "source_url": "https://web.archive.org/web/20130115115225/http://craftsmanship.sv.cmu.edu:80/exercises/coin-change-kata" +} diff --git a/exercises/practice/change/.meta/example.ua b/exercises/practice/change/.meta/example.ua new file mode 100644 index 0000000..3bf1563 --- /dev/null +++ b/exercises/practice/change/.meta/example.ua @@ -0,0 +1,14 @@ +ShouldUpdate ← ⨬(>+1∩(⨬(⧻|∘)≍∞.)|0) ≍∞. +Update ← ⍜(⊡|□◌) ⊃(⋅⋅∘|⋅⋅⋅⋅∘|⊂⊙⋅⋅∘) +Process ← ( + ⊙⊙◌◡⊃(°□⊡⊙⋅⋅|°□⊡⋅⊙⋅)◡(⌵-)°⊟ + ◡ShouldUpdate + ⨬(⋅⋅⋅⋅∘|Update) +) +Amounts ← ⍜(⊢|□[]◌) ↯[+1]:∞ +Combinations ← ▽⊸≡(≤°⊟)/⊂⊞⊂ ⊃(+1⇡◌|∘|⋅Amounts) +Coins ← ( + ◇⍆⊣ ∧Process Combinations + ⨬(∘|⍤"can't make target with given coins")=∞. +) +Change ← ⨬(⍤"target can't be negative"|[]|Coins)+1±, diff --git a/exercises/practice/change/.meta/tests.toml b/exercises/practice/change/.meta/tests.toml new file mode 100644 index 0000000..2d2f44b --- /dev/null +++ b/exercises/practice/change/.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. + +[d0ebd0e1-9d27-4609-a654-df5c0ba1d83a] +description = "change for 1 cent" + +[36887bea-7f92-4a9c-b0cc-c0e886b3ecc8] +description = "single coin change" + +[cef21ccc-0811-4e6e-af44-f011e7eab6c6] +description = "multiple coin change" + +[d60952bc-0c1a-4571-bf0c-41be72690cb3] +description = "change with Lilliputian Coins" + +[408390b9-fafa-4bb9-b608-ffe6036edb6c] +description = "change with Lower Elbonia Coins" + +[7421a4cb-1c48-4bf9-99c7-7f049689132f] +description = "large target values" + +[f79d2e9b-0ae3-4d6a-bb58-dc978b0dba28] +description = "possible change without unit coins available" + +[9a166411-d35d-4f7f-a007-6724ac266178] +description = "another possible change without unit coins available" + +[ce0f80d5-51c3-469d-818c-3e69dbd25f75] +description = "a greedy approach is not optimal" + +[bbbcc154-e9e9-4209-a4db-dd6d81ec26bb] +description = "no coins make 0 change" + +[c8b81d5a-49bd-4b61-af73-8ee5383a2ce1] +description = "error testing for change smaller than the smallest of coins" + +[3c43e3e4-63f9-46ac-9476-a67516e98f68] +description = "error if no combination can add up to target" + +[8fe1f076-9b2d-4f44-89fe-8a6ccd63c8f3] +description = "cannot find negative change values" diff --git a/exercises/practice/change/change.ua b/exercises/practice/change/change.ua new file mode 100644 index 0000000..88b5a2d --- /dev/null +++ b/exercises/practice/change/change.ua @@ -0,0 +1,3 @@ +# Determine the fewest number of coins for a given target value +# Change ? Coins Target +Change ← |2 ⊙⋅(⍤ "Please implement Change" 0) diff --git a/exercises/practice/change/tests.ua b/exercises/practice/change/tests.ua new file mode 100644 index 0000000..2e93dce --- /dev/null +++ b/exercises/practice/change/tests.ua @@ -0,0 +1,70 @@ +~ "change.ua" ~ Change + +# Change for 1 cent +Coins ← [1 5 10 25] +Target ← 1 +Expected ← [1] +⍤⤙≍ Expected Change Coins Target + +# Single coin change +Coins ← [1 5 10 25 100] +Target ← 25 +Expected ← [25] +⍤⤙≍ Expected Change Coins Target + +# Multiple coin change +Coins ← [1 5 10 25 100] +Target ← 15 +Expected ← [5 10] +⍤⤙≍ Expected Change Coins Target + +# Change with Lilliputian Coins +Coins ← [1 4 15 20 50] +Target ← 23 +Expected ← [4 4 15] +⍤⤙≍ Expected Change Coins Target + +# Change with Lower Elbonia Coins +Coins ← [1 5 10 21 25] +Target ← 63 +Expected ← [21 21 21] +⍤⤙≍ Expected Change Coins Target + +# Large target values +Coins ← [1 2 5 10 20 50 100] +Target ← 999 +Expected ← [2 2 5 20 20 50 100 100 100 100 100 100 100 100 100] +⍤⤙≍ Expected Change Coins Target + +# Possible change without unit coins available +Coins ← [2 5 10 20 50] +Target ← 21 +Expected ← [2 2 2 5 10] +⍤⤙≍ Expected Change Coins Target + +# Another possible change without unit coins available +Coins ← [4 5] +Target ← 27 +Expected ← [4 4 4 5 5 5] +⍤⤙≍ Expected Change Coins Target + +# No coins make 0 change +Coins ← [1 5 10 21 25] +Target ← 0 +Expected ← [] +⍤⤙≍ Expected Change Coins Target + +# Error testing for change smaller than the smallest of coins +Coins ← [5 10] +Target ← 3 +⍤⤙≍ "can't make target with given coins" ⍣(Change Coins Target) + +# Error if no combination can add up to target +Coins ← [5 10] +Target ← 94 +⍤⤙≍ "can't make target with given coins" ⍣(Change Coins Target) + +# Cannot find negative change values +Coins ← [1 2 5] +Target ← ¯5 +⍤⤙≍ "target can't be negative" ⍣(Change Coins Target)