From 53146866177bce0288dba222e21899a636189fde Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A1s=20B=20Nagy?= <20251272+BNAndras@users.noreply.github.com> Date: Tue, 31 Oct 2023 23:21:55 -0700 Subject: [PATCH] Add flatten-array (#51) --- config.json | 8 + .../.docs/instructions-append.md | 5 + .../flatten-array/.docs/instructions.md | 11 + .../practice/flatten-array/.meta/config.json | 19 ++ .../practice/flatten-array/.meta/example.arr | 22 ++ .../practice/flatten-array/.meta/tests.toml | 43 ++++ .../flatten-array/flatten-array-test.arr | 207 ++++++++++++++++++ .../practice/flatten-array/flatten-array.arr | 7 + 8 files changed, 322 insertions(+) create mode 100644 exercises/practice/flatten-array/.docs/instructions-append.md create mode 100644 exercises/practice/flatten-array/.docs/instructions.md create mode 100644 exercises/practice/flatten-array/.meta/config.json create mode 100644 exercises/practice/flatten-array/.meta/example.arr create mode 100644 exercises/practice/flatten-array/.meta/tests.toml create mode 100644 exercises/practice/flatten-array/flatten-array-test.arr create mode 100644 exercises/practice/flatten-array/flatten-array.arr diff --git a/config.json b/config.json index 70e803e..fef42c2 100644 --- a/config.json +++ b/config.json @@ -156,6 +156,14 @@ "prerequisites": [], "difficulty": 2 }, + { + "slug": "flatten-array", + "name": "Flatten List", + "uuid": "23b5a864-186c-4a4d-ba32-83608b0d18f6", + "practices": [], + "prerequisites": [], + "difficulty": 2 + }, { "slug": "grains", "name": "Grains", diff --git a/exercises/practice/flatten-array/.docs/instructions-append.md b/exercises/practice/flatten-array/.docs/instructions-append.md new file mode 100644 index 0000000..01209f6 --- /dev/null +++ b/exercises/practice/flatten-array/.docs/instructions-append.md @@ -0,0 +1,5 @@ +# Instructions append + +This exercise is implemented using the built-in [List] datatype, not RawArrays. + +[list]: https://pyret.org/docs/latest/lists.html diff --git a/exercises/practice/flatten-array/.docs/instructions.md b/exercises/practice/flatten-array/.docs/instructions.md new file mode 100644 index 0000000..51bea67 --- /dev/null +++ b/exercises/practice/flatten-array/.docs/instructions.md @@ -0,0 +1,11 @@ +# Instructions + +Take a nested list and return a single flattened list with all values except nil/null. + +The challenge is to write a function that accepts an arbitrarily-deep nested list-like structure and returns a flattened structure without any nil/null values. + +For example: + +input: [1,[2,3,null,4],[null],5] + +output: [1,2,3,4,5] diff --git a/exercises/practice/flatten-array/.meta/config.json b/exercises/practice/flatten-array/.meta/config.json new file mode 100644 index 0000000..2da5156 --- /dev/null +++ b/exercises/practice/flatten-array/.meta/config.json @@ -0,0 +1,19 @@ +{ + "authors": [ + "BNAndras" + ], + "files": { + "solution": [ + "flatten-array.arr" + ], + "test": [ + "flatten-array-test.arr" + ], + "example": [ + ".meta/example.arr" + ] + }, + "blurb": "Take a nested list and return a single list with all values except nil/null.", + "source": "Interview Question", + "source_url": "https://reference.wolfram.com/language/ref/Flatten.html" +} diff --git a/exercises/practice/flatten-array/.meta/example.arr b/exercises/practice/flatten-array/.meta/example.arr new file mode 100644 index 0000000..0c6e3d7 --- /dev/null +++ b/exercises/practice/flatten-array/.meta/example.arr @@ -0,0 +1,22 @@ +use context essentials2020 + +provide: flatten end + +import lists as L + +fun flatten(lst): + lst.foldr(lam(elt, acc): + ask: + | elt == nothing then: + acc + | is-empty(elt) then: + acc + | is-link(elt) then: + result = flatten(elt) + result.append(acc) + | otherwise: + L.push(acc, elt) + end + end, + [list: ]) +end diff --git a/exercises/practice/flatten-array/.meta/tests.toml b/exercises/practice/flatten-array/.meta/tests.toml new file mode 100644 index 0000000..6300219 --- /dev/null +++ b/exercises/practice/flatten-array/.meta/tests.toml @@ -0,0 +1,43 @@ +# 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. + +[8c71dabd-da60-422d-a290-4a571471fb14] +description = "empty" + +[d268b919-963c-442d-9f07-82b93f1b518c] +description = "no nesting" + +[3f15bede-c856-479e-bb71-1684b20c6a30] +description = "flattens a nested array" + +[c84440cc-bb3a-48a6-862c-94cf23f2815d] +description = "flattens array with just integers present" + +[d3d99d39-6be5-44f5-a31d-6037d92ba34f] +description = "5 level nesting" + +[d572bdba-c127-43ed-bdcd-6222ac83d9f7] +description = "6 level nesting" + +[0705a8e5-dc86-4cec-8909-150c5e54fa9c] +description = "null values are omitted from the final result" + +[c6cf26de-8ccd-4410-84bd-b9efd88fd2bc] +description = "consecutive null values at the front of the list are omitted from the final result" + +[382c5242-587e-4577-b8ce-a5fb51e385a1] +description = "consecutive null values in the middle of the list are omitted from the final result" + +[ef1d4790-1b1e-4939-a179-51ace0829dbd] +description = "6 level nest list with null values" + +[85721643-705a-4150-93ab-7ae398e2942d] +description = "all values in nested list are null" diff --git a/exercises/practice/flatten-array/flatten-array-test.arr b/exercises/practice/flatten-array/flatten-array-test.arr new file mode 100644 index 0000000..c5590c3 --- /dev/null +++ b/exercises/practice/flatten-array/flatten-array-test.arr @@ -0,0 +1,207 @@ +use context essentials2020 + +include file("flatten-array.arr") + +#| + When working offline, all tests except the first one are skipped by default. + Once you get the first test running, unskip the next one until all tests pass locally. + Check the block comment below for further details. +|# + +fun empty-list(): + check "empty": + input = [list: ] + + expected = [list: ] + + flatten(input) is expected + end +end + +fun no-nesting(): + check "no nesting": + input = [list: 0, 1, 2] + + expected = [list: 0, 1, 2] + + flatten(input) is expected + end +end + +fun nested-list(): + check "flattens a nested list": + input = [list: [list: ]] + + expected = [list: ] + + flatten(input) is expected + end +end + +fun numeric-list(): + check "flattens list with just integers present": + input = [list: 1, [list: 2, 3, 4, 5, 6, 7], 8] + + expected = [list: 1, 2, 3, 4, 5, 6, 7, 8] + + flatten(input) is expected + end +end + +fun five-levels(): + check "5 level nesting": + input = [list: + 0, + 2, + [list: + [list: 2, 3], + 8, + 100, + 4, + [list: + [list: + [list: 50]]]], + -2] + + expected = [list: + 0, + 2, + 2, + 3, + 8, + 100, + 4, + 50, + -2] + + flatten(input) is expected + end +end + +fun six-levels(): + check "6 level nesting": + input = [list: + 1, + [list: + 2, + [list: [list: 3]], + [list: + 4, + [list: [list: 5]]], + 6, + 7], + 8] + + expected = [list: + 1, + 2, + 3, + 4, + 5, + 6, + 7, + 8] + + flatten(input) is expected + end +end + +fun omit-a-nothing(): + check "nothing values are omitted from the final result": + input = [list: 1, 2, nothing] + + expected = [list: 1, 2] + + flatten(input) is expected + end +end + +fun omit-nothings-from-beginning(): + check "consecutive nothing values at the front of the list are omitted from the final result": + input = [list: nothing, nothing, 3] + + expected = [list: 3] + + flatten(input) is expected + end +end + +fun omit-nothings-from-middle(): + check "consecutive nothing values in the middle of the list are omitted from the final result": + input = [list: 1, nothing, nothing, 4] + + expected = [list: 1, 4] + + flatten(input) is expected + end +end + +fun six-levels-with-nothings(): + check "6 level nest list with nothing values": + input = [list: + 0, + 2, + [list: + [list: 2, 3], + 8, + [list: [list: 100 ]], + nothing, + [list: [list: nothing]]], + -2] + + expected = [list: + 0, + 2, + 2, + 3, + 8, + 100, + -2] + + flatten(input) is expected + end +end + +fun all-nothings(): + check "all values in nested list are nothing": + input = [list: + nothing, + [list: + [list: + [list: nothing]]], + nothing, + nothing, + [list: + [list: + nothing, + nothing], + nothing], + nothing] + + expected = [list: ] + + flatten(input) is expected + end +end + +#| + Code to run each test. Each line corresponds to a test above and whether it should be run. + To mark a test to be run, replace `false` with `true` on that same line after the comma. + test(test-a, true) will be run. test(test-a, false) will be skipped. +|# + +data TestRun: test(run, active) end + +[list: + test(empty-list, true), + test(no-nesting, false), + test(nested-list, false), + test(numeric-list, false), + test(five-levels, false), + test(six-levels, false), + test(omit-a-nothing, false), + test(omit-nothings-from-beginning, false), + test(omit-nothings-from-middle, false), + test(six-levels-with-nothings, false), + test(all-nothings, false) +].each(lam(t): when t.active: t.run() end end) \ No newline at end of file diff --git a/exercises/practice/flatten-array/flatten-array.arr b/exercises/practice/flatten-array/flatten-array.arr new file mode 100644 index 0000000..81565d2 --- /dev/null +++ b/exercises/practice/flatten-array/flatten-array.arr @@ -0,0 +1,7 @@ +use context essentials2020 + +provide: flatten end + +fun flatten(lst): + raise("please implement the flatten function") +end