diff --git a/config.json b/config.json index ddfac3a9..ca83232d 100644 --- a/config.json +++ b/config.json @@ -1833,6 +1833,18 @@ "recursion" ], "difficulty": 4 + }, + { + "slug": "zebra-puzzle", + "name": "Zebra Puzzle", + "uuid": "82a312b6-5d71-4119-b3b0-211d572c17c8", + "practices": [ + "results" + ], + "prerequisites": [ + "recursion" + ], + "difficulty": 9 } ] }, diff --git a/exercises/practice/zebra-puzzle/.docs/instructions.md b/exercises/practice/zebra-puzzle/.docs/instructions.md new file mode 100644 index 00000000..c666e33c --- /dev/null +++ b/exercises/practice/zebra-puzzle/.docs/instructions.md @@ -0,0 +1,32 @@ +# Instructions + +Your task is to solve the Zebra Puzzle to find the answer to these two questions: + +- Which of the residents drinks water? +- Who owns the zebra? + +## Puzzle + +The following 15 statements are all known to be true: + +1. There are five houses. +2. The Englishman lives in the red house. +3. The Spaniard owns the dog. +4. Coffee is drunk in the green house. +5. The Ukrainian drinks tea. +6. The green house is immediately to the right of the ivory house. +7. The Old Gold smoker owns snails. +8. Kools are smoked in the yellow house. +9. Milk is drunk in the middle house. +10. The Norwegian lives in the first house. +11. The man who smokes Chesterfields lives in the house next to the man with the fox. +12. Kools are smoked in the house next to the house where the horse is kept. +13. The Lucky Strike smoker drinks orange juice. +14. The Japanese smokes Parliaments. +15. The Norwegian lives next to the blue house. + +Additionally, each of the five houses is painted a different color, and their inhabitants are of different national extractions, own different pets, drink different beverages and smoke different brands of cigarettes. + +~~~~exercism/note +There are 24 billion (5!⁵ = 24,883,200,000) possible solutions, so try ruling out as many solutions as possible. +~~~~ diff --git a/exercises/practice/zebra-puzzle/.docs/introduction.md b/exercises/practice/zebra-puzzle/.docs/introduction.md new file mode 100644 index 00000000..33d688fd --- /dev/null +++ b/exercises/practice/zebra-puzzle/.docs/introduction.md @@ -0,0 +1,15 @@ +# Introduction + +The Zebra Puzzle is a famous logic puzzle in which there are five houses, each painted a different color. +The houses have different inhabitants, who have different nationalities, own different pets, drink different beverages and smoke different brands of cigarettes. + +To help you solve the puzzle, you're given 15 statements describing the solution. +However, only by combining the information in _all_ statements will you be able to find the solution to the puzzle. + +~~~~exercism/note +The Zebra Puzzle is a [Constraint satisfaction problem (CSP)][constraint-satisfaction-problem]. +In such a problem, you have a set of possible values and a set of constraints that limit which values are valid. +Another well-known CSP is Sudoku. + +[constraint-satisfaction-problem]: https://en.wikipedia.org/wiki/Constraint_satisfaction_problem +~~~~ diff --git a/exercises/practice/zebra-puzzle/.meta/config.json b/exercises/practice/zebra-puzzle/.meta/config.json new file mode 100644 index 00000000..6a875346 --- /dev/null +++ b/exercises/practice/zebra-puzzle/.meta/config.json @@ -0,0 +1,17 @@ +{ + "authors": [], + "files": { + "solution": [ + "src/zebra_puzzle.gleam" + ], + "test": [ + "test/zebra_puzzle_test.gleam" + ], + "example": [ + ".meta/example.gleam" + ] + }, + "blurb": "Solve the zebra puzzle.", + "source": "Wikipedia", + "source_url": "https://en.wikipedia.org/wiki/Zebra_Puzzle" +} diff --git a/exercises/practice/zebra-puzzle/.meta/example.gleam b/exercises/practice/zebra-puzzle/.meta/example.gleam new file mode 100644 index 00000000..682d33b2 --- /dev/null +++ b/exercises/practice/zebra-puzzle/.meta/example.gleam @@ -0,0 +1,254 @@ +import gleam/dict.{type Dict} +import gleam/list +import gleam/result + +pub fn water_drinker() -> Result(String, Nil) { + solve() + |> result.map(fn(solution) { solution.water_drinker }) +} + +pub fn zebra_owner() -> Result(String, Nil) { + solve() + |> result.map(fn(solution) { solution.zebra_owner }) +} + +type Solution { + Solution(water_drinker: String, zebra_owner: String) +} + +type Parameters = + Dict(String, Int) + +type Nationalities = + Dict(Int, String) + +fn solve() -> Result(Solution, Nil) { + solve_for_colour( + houses() + |> list.permutations(), + dict.new(), + ) +} + +fn houses() { + // clue 1 + [1, 2, 3, 4, 5] +} + +fn right_of(a: Int, b: Int) -> Bool { + a == b + 1 +} + +fn next_to(a: Int, b: Int) -> Bool { + right_of(a, b) || right_of(b, a) +} + +fn first() { + 1 +} + +fn middle() { + 3 +} + +fn solve_for_colour( + permutations: List(List(Int)), + parameters: Parameters, +) -> Result(Solution, Nil) { + case permutations { + [] -> Error(Nil) + [perm, ..rest] -> { + let assert [red, green, ivory, yellow, blue] = perm + + // clue 6 + case right_of(green, ivory) { + False -> solve_for_colour(rest, parameters) + True -> { + let parameters = + parameters + |> dict.insert("red", red) + |> dict.insert("blue", blue) + |> dict.insert("green", green) + |> dict.insert("ivory", ivory) + |> dict.insert("yellow", yellow) + case + solve_for_nationalities( + houses() + |> list.permutations(), + parameters, + ) + { + Error(Nil) -> solve_for_colour(rest, parameters) + Ok(result) -> Ok(result) + } + } + } + } + } +} + +fn solve_for_nationalities( + permutations: List(List(Int)), + parameters: Parameters, +) -> Result(Solution, Nil) { + case permutations { + [] -> Error(Nil) + [perm, ..rest] -> { + let assert [english, spanish, ukranian, norwegian, japanese] = perm + let assert Ok(red) = dict.get(parameters, "red") + let assert Ok(blue) = dict.get(parameters, "blue") + + // clues: 2, 10, 15 + case english == red && norwegian == first() && next_to(norwegian, blue) { + False -> solve_for_nationalities(rest, parameters) + True -> { + let parameters = + parameters + |> dict.insert("english", english) + |> dict.insert("spanish", spanish) + |> dict.insert("ukranian", ukranian) + |> dict.insert("japanese", japanese) + |> dict.insert("norwegian", norwegian) + let nationalities = + dict.from_list([ + #(english, "EnglishMan"), + #(spanish, "Spaniard"), + #(ukranian, "Ukranian"), + #(japanese, "Japanese"), + #(norwegian, "Norwegian"), + ]) + case + solve_for_beverages( + houses() + |> list.permutations(), + parameters, + nationalities, + ) + { + Error(Nil) -> solve_for_nationalities(rest, parameters) + Ok(result) -> Ok(result) + } + } + } + } + } +} + +fn solve_for_beverages( + permutations: List(List(Int)), + parameters: Parameters, + nationalities: Nationalities, +) -> Result(Solution, Nil) { + case permutations { + [] -> Error(Nil) + [perm, ..rest] -> { + let assert [coffee, tea, milk, orange_juice, water] = perm + let assert Ok(green) = dict.get(parameters, "green") + let assert Ok(ukranian) = dict.get(parameters, "ukranian") + + // clues: 4, 5, 9 + case coffee == green && tea == ukranian && milk == middle() { + False -> solve_for_beverages(rest, parameters, nationalities) + True -> { + let parameters = + parameters + |> dict.insert("tea", tea) + |> dict.insert("milk", milk) + |> dict.insert("water", water) + |> dict.insert("coffee", coffee) + |> dict.insert("orange_juice", orange_juice) + case + solve_for_cigarettes( + houses() + |> list.permutations(), + parameters, + nationalities, + ) + { + Error(Nil) -> solve_for_beverages(rest, parameters, nationalities) + Ok(result) -> Ok(result) + } + } + } + } + } +} + +fn solve_for_cigarettes( + permutations: List(List(Int)), + parameters: Parameters, + nationalities: Nationalities, +) -> Result(Solution, Nil) { + case permutations { + [] -> Error(Nil) + [perm, ..rest] -> { + let assert [old_gold, kools, chesterfields, lucky_strike, parliaments] = + perm + let assert Ok(yellow) = dict.get(parameters, "yellow") + let assert Ok(japanese) = dict.get(parameters, "japanese") + let assert Ok(orange_juice) = dict.get(parameters, "orange_juice") + + // clues: 8, 13, 14 + case + kools == yellow + && lucky_strike == orange_juice + && parliaments == japanese + { + False -> solve_for_cigarettes(rest, parameters, nationalities) + True -> { + let parameters = + parameters + |> dict.insert("kools", kools) + |> dict.insert("old_gold", old_gold) + |> dict.insert("lucky_strike", lucky_strike) + |> dict.insert("parliaments", parliaments) + |> dict.insert("chesterfields", chesterfields) + case + solve_for_pets( + houses() + |> list.permutations(), + parameters, + nationalities, + ) + { + Error(Nil) -> solve_for_cigarettes(rest, parameters, nationalities) + Ok(result) -> Ok(result) + } + } + } + } + } +} + +fn solve_for_pets( + permutations: List(List(Int)), + parameters: Parameters, + nationalities: Nationalities, +) -> Result(Solution, Nil) { + case permutations { + [] -> Error(Nil) + [perm, ..rest] -> { + let assert [dog, snails, fox, horse, zebra] = perm + let assert Ok(kools) = dict.get(parameters, "kools") + let assert Ok(spanish) = dict.get(parameters, "spanish") + let assert Ok(old_gold) = dict.get(parameters, "old_gold") + let assert Ok(chesterfields) = dict.get(parameters, "chesterfields") + + // clues: 3, 7, 11, 12 + case + dog == spanish + && snails == old_gold + && next_to(fox, chesterfields) + && next_to(horse, kools) + { + False -> solve_for_pets(rest, parameters, nationalities) + True -> { + let assert Ok(water) = dict.get(parameters, "water") + let assert Ok(water_owner) = dict.get(nationalities, water) + let assert Ok(zebra_owner) = dict.get(nationalities, zebra) + Ok(Solution(water_owner, zebra_owner)) + } + } + } + } +} diff --git a/exercises/practice/zebra-puzzle/.meta/tests.toml b/exercises/practice/zebra-puzzle/.meta/tests.toml new file mode 100644 index 00000000..56c21c7a --- /dev/null +++ b/exercises/practice/zebra-puzzle/.meta/tests.toml @@ -0,0 +1,16 @@ +# 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. + +[16efb4e4-8ad7-4d5e-ba96-e5537b66fd42] +description = "resident who drinks water" + +[084d5b8b-24e2-40e6-b008-c800da8cd257] +description = "resident who owns zebra" diff --git a/exercises/practice/zebra-puzzle/gleam.toml b/exercises/practice/zebra-puzzle/gleam.toml new file mode 100644 index 00000000..bfae685c --- /dev/null +++ b/exercises/practice/zebra-puzzle/gleam.toml @@ -0,0 +1,12 @@ +name = "zebra_puzzle" +version = "0.1.0" + +[dependencies] +gleam_bitwise = "~> 1.2" +gleam_otp = "~> 0.7 or ~> 1.0" +gleam_stdlib = "~> 0.32 or ~> 1.0" +simplifile = "~> 1.0" +gleam_erlang = ">= 0.25.0 and < 1.0.0" + +[dev-dependencies] +exercism_test_runner = "~> 1.4" diff --git a/exercises/practice/zebra-puzzle/manifest.toml b/exercises/practice/zebra-puzzle/manifest.toml new file mode 100644 index 00000000..072155d1 --- /dev/null +++ b/exercises/practice/zebra-puzzle/manifest.toml @@ -0,0 +1,27 @@ +# This file was generated by Gleam +# You typically do not need to edit this file + +packages = [ + { name = "argv", version = "1.0.1", build_tools = ["gleam"], requirements = [], otp_app = "argv", source = "hex", outer_checksum = "A6E9009E50BBE863EB37D963E4315398D41A3D87D0075480FC244125808F964A" }, + { name = "exercism_test_runner", version = "1.7.0", build_tools = ["gleam"], requirements = ["argv", "gap", "glance", "gleam_community_ansi", "gleam_erlang", "gleam_json", "gleam_stdlib", "simplifile"], otp_app = "exercism_test_runner", source = "hex", outer_checksum = "2FC1BADB19BEC2AE77BFD2D3A606A014C85412A7B874CAFC4BA8CF04B0B257CD" }, + { name = "gap", version = "1.1.0", build_tools = ["gleam"], requirements = ["gleam_community_ansi", "gleam_stdlib"], otp_app = "gap", source = "hex", outer_checksum = "2EE1B0A17E85CF73A0C1D29DA315A2699117A8F549C8E8D89FA8261BE41EDEB1" }, + { name = "glance", version = "0.8.2", build_tools = ["gleam"], requirements = ["gleam_stdlib", "glexer"], otp_app = "glance", source = "hex", outer_checksum = "ACF09457E8B564AD7A0D823DAFDD326F58263C01ACB0D432A9BEFDEDD1DA8E73" }, + { name = "gleam_bitwise", version = "1.3.1", build_tools = ["gleam"], requirements = [], otp_app = "gleam_bitwise", source = "hex", outer_checksum = "B36E1D3188D7F594C7FD4F43D0D2CE17561DE896202017548578B16FE1FE9EFC" }, + { name = "gleam_community_ansi", version = "1.4.0", build_tools = ["gleam"], requirements = ["gleam_community_colour", "gleam_stdlib"], otp_app = "gleam_community_ansi", source = "hex", outer_checksum = "FE79E08BF97009729259B6357EC058315B6FBB916FAD1C2FF9355115FEB0D3A4" }, + { name = "gleam_community_colour", version = "1.3.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_community_colour", source = "hex", outer_checksum = "A49A5E3AE8B637A5ACBA80ECB9B1AFE89FD3D5351FF6410A42B84F666D40D7D5" }, + { name = "gleam_erlang", version = "0.25.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_erlang", source = "hex", outer_checksum = "054D571A7092D2A9727B3E5D183B7507DAB0DA41556EC9133606F09C15497373" }, + { name = "gleam_json", version = "1.0.0", build_tools = ["gleam"], requirements = ["gleam_stdlib", "thoas"], otp_app = "gleam_json", source = "hex", outer_checksum = "8B197DD5D578EA6AC2C0D4BDC634C71A5BCA8E7DB5F47091C263ECB411A60DF3" }, + { name = "gleam_otp", version = "0.10.0", build_tools = ["gleam"], requirements = ["gleam_erlang", "gleam_stdlib"], otp_app = "gleam_otp", source = "hex", outer_checksum = "0B04FE915ACECE539B317F9652CAADBBC0F000184D586AAAF2D94C100945D72B" }, + { name = "gleam_stdlib", version = "0.36.0", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "C0D14D807FEC6F8A08A7C9EF8DFDE6AE5C10E40E21325B2B29365965D82EB3D4" }, + { name = "glexer", version = "0.7.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "glexer", source = "hex", outer_checksum = "4484942A465482A0A100936E1E5F12314DB4B5AC0D87575A7B9E9062090B96BE" }, + { name = "simplifile", version = "1.5.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "simplifile", source = "hex", outer_checksum = "EB9AA8E65E5C1E3E0FDCFC81BC363FD433CB122D7D062750FFDF24DE4AC40116" }, + { name = "thoas", version = "0.4.1", build_tools = ["rebar3"], requirements = [], otp_app = "thoas", source = "hex", outer_checksum = "4918D50026C073C4AB1388437132C77A6F6F7C8AC43C60C13758CC0ADCE2134E" }, +] + +[requirements] +exercism_test_runner = { version = "~> 1.4" } +gleam_bitwise = { version = "~> 1.2" } +gleam_erlang = { version = ">= 0.25.0 and < 1.0.0"} +gleam_otp = { version = "~> 0.7 or ~> 1.0" } +gleam_stdlib = { version = "~> 0.32 or ~> 1.0" } +simplifile = { version = "~> 1.0" } diff --git a/exercises/practice/zebra-puzzle/src/zebra_puzzle.gleam b/exercises/practice/zebra-puzzle/src/zebra_puzzle.gleam new file mode 100644 index 00000000..629e61d0 --- /dev/null +++ b/exercises/practice/zebra-puzzle/src/zebra_puzzle.gleam @@ -0,0 +1,7 @@ +pub fn water_drinker() -> Result(String, Nil) { + todo +} + +pub fn zebra_owner() -> Result(String, Nil) { + todo +} diff --git a/exercises/practice/zebra-puzzle/test/zebra_puzzle_test.gleam b/exercises/practice/zebra-puzzle/test/zebra_puzzle_test.gleam new file mode 100644 index 00000000..a6f611a1 --- /dev/null +++ b/exercises/practice/zebra-puzzle/test/zebra_puzzle_test.gleam @@ -0,0 +1,17 @@ +import exercism/should +import exercism/test_runner +import zebra_puzzle + +pub fn main() { + test_runner.main() +} + +pub fn drinks_water_test() { + zebra_puzzle.water_drinker() + |> should.equal(Ok("Norwegian")) +} + +pub fn owns_zebra_test() { + zebra_puzzle.zebra_owner() + |> should.equal(Ok("Japanese")) +}