From ac58c65fe3549758ecbc63aa8c96f6dbcad3342b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A1s=20B=20Nagy?= <20251272+BNAndras@users.noreply.github.com> Date: Sun, 15 Dec 2024 10:35:30 -0800 Subject: [PATCH 1/2] Add `luhn` --- config.json | 8 ++ exercises/practice/luhn/.docs/instructions.md | 65 ++++++++++ exercises/practice/luhn/.meta/config.json | 19 +++ exercises/practice/luhn/.meta/src/example.art | 16 +++ exercises/practice/luhn/.meta/tests.toml | 76 ++++++++++++ exercises/practice/luhn/src/luhn.art | 3 + exercises/practice/luhn/tester.art | 3 + exercises/practice/luhn/tests/test-luhn.art | 114 ++++++++++++++++++ 8 files changed, 304 insertions(+) create mode 100644 exercises/practice/luhn/.docs/instructions.md create mode 100644 exercises/practice/luhn/.meta/config.json create mode 100644 exercises/practice/luhn/.meta/src/example.art create mode 100644 exercises/practice/luhn/.meta/tests.toml create mode 100644 exercises/practice/luhn/src/luhn.art create mode 100644 exercises/practice/luhn/tester.art create mode 100644 exercises/practice/luhn/tests/test-luhn.art diff --git a/config.json b/config.json index c3f17a3..7d9c147 100644 --- a/config.json +++ b/config.json @@ -189,6 +189,14 @@ "prerequisites": [], "difficulty": 2 }, + { + "slug": "luhn", + "name": "Luhn", + "uuid": "b3694bc0-727b-4b48-b568-de39e8d2c4aa", + "practices": [], + "prerequisites": [], + "difficulty": 2 + }, { "slug": "nucleotide-count", "name": "Nucleotide Count", diff --git a/exercises/practice/luhn/.docs/instructions.md b/exercises/practice/luhn/.docs/instructions.md new file mode 100644 index 0000000..49934c1 --- /dev/null +++ b/exercises/practice/luhn/.docs/instructions.md @@ -0,0 +1,65 @@ +# Instructions + +Given a number determine whether or not it is valid per the Luhn formula. + +The [Luhn algorithm][luhn] is a simple checksum formula used to validate a variety of identification numbers, such as credit card numbers and Canadian Social Insurance Numbers. + +The task is to check if a given string is valid. + +## Validating a Number + +Strings of length 1 or less are not valid. +Spaces are allowed in the input, but they should be stripped before checking. +All other non-digit characters are disallowed. + +### Example 1: valid credit card number + +```text +4539 3195 0343 6467 +``` + +The first step of the Luhn algorithm is to double every second digit, starting from the right. +We will be doubling + +```text +4539 3195 0343 6467 +↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ (double these) +``` + +If doubling the number results in a number greater than 9 then subtract 9 from the product. +The results of our doubling: + +```text +8569 6195 0383 3437 +``` + +Then sum all of the digits: + +```text +8+5+6+9+6+1+9+5+0+3+8+3+3+4+3+7 = 80 +``` + +If the sum is evenly divisible by 10, then the number is valid. +This number is valid! + +### Example 2: invalid credit card number + +```text +8273 1232 7352 0569 +``` + +Double the second digits, starting from the right + +```text +7253 2262 5312 0539 +``` + +Sum the digits + +```text +7+2+5+3+2+2+6+2+5+3+1+2+0+5+3+9 = 57 +``` + +57 is not evenly divisible by 10, so this number is not valid. + +[luhn]: https://en.wikipedia.org/wiki/Luhn_algorithm diff --git a/exercises/practice/luhn/.meta/config.json b/exercises/practice/luhn/.meta/config.json new file mode 100644 index 0000000..9ffa9bd --- /dev/null +++ b/exercises/practice/luhn/.meta/config.json @@ -0,0 +1,19 @@ +{ + "authors": [ + "BNAndras" + ], + "files": { + "solution": [ + "src/luhn.art" + ], + "test": [ + "tests/test-luhn.art" + ], + "example": [ + ".meta/src/example.art" + ] + }, + "blurb": "Given a number determine whether or not it is valid per the Luhn formula.", + "source": "The Luhn Algorithm on Wikipedia", + "source_url": "https://en.wikipedia.org/wiki/Luhn_algorithm" +} diff --git a/exercises/practice/luhn/.meta/src/example.art b/exercises/practice/luhn/.meta/src/example.art new file mode 100644 index 0000000..9893de1 --- /dev/null +++ b/exercises/practice/luhn/.meta/src/example.art @@ -0,0 +1,16 @@ + +luhn?: function [value][ + cleaned: replace value " " "" + if 2 > size cleaned -> return false + if not? every? cleaned 'x -> between? x '0' '9' -> return false + sum: 0 + + sum: fold.seed:0.with:'i reverse cleaned [acc, x] [ + n: to :integer to :string x + if odd? i -> n: n * 2 + if n > 9 -> n: n - 9 + acc + n + ] + + 0 = sum % 10 +] diff --git a/exercises/practice/luhn/.meta/tests.toml b/exercises/practice/luhn/.meta/tests.toml new file mode 100644 index 0000000..c0be0c4 --- /dev/null +++ b/exercises/practice/luhn/.meta/tests.toml @@ -0,0 +1,76 @@ +# 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. + +[792a7082-feb7-48c7-b88b-bbfec160865e] +description = "single digit strings can not be valid" + +[698a7924-64d4-4d89-8daa-32e1aadc271e] +description = "a single zero is invalid" + +[73c2f62b-9b10-4c9f-9a04-83cee7367965] +description = "a simple valid SIN that remains valid if reversed" + +[9369092e-b095-439f-948d-498bd076be11] +description = "a simple valid SIN that becomes invalid if reversed" + +[8f9f2350-1faf-4008-ba84-85cbb93ffeca] +description = "a valid Canadian SIN" + +[1cdcf269-6560-44fc-91f6-5819a7548737] +description = "invalid Canadian SIN" + +[656c48c1-34e8-4e60-9a5a-aad8a367810a] +description = "invalid credit card" + +[20e67fad-2121-43ed-99a8-14b5b856adb9] +description = "invalid long number with an even remainder" + +[7e7c9fc1-d994-457c-811e-d390d52fba5e] +description = "invalid long number with a remainder divisible by 5" + +[ad2a0c5f-84ed-4e5b-95da-6011d6f4f0aa] +description = "valid number with an even number of digits" + +[ef081c06-a41f-4761-8492-385e13c8202d] +description = "valid number with an odd number of spaces" + +[bef66f64-6100-4cbb-8f94-4c9713c5e5b2] +description = "valid strings with a non-digit added at the end become invalid" + +[2177e225-9ce7-40f6-b55d-fa420e62938e] +description = "valid strings with punctuation included become invalid" + +[ebf04f27-9698-45e1-9afe-7e0851d0fe8d] +description = "valid strings with symbols included become invalid" + +[08195c5e-ce7f-422c-a5eb-3e45fece68ba] +description = "single zero with space is invalid" + +[12e63a3c-f866-4a79-8c14-b359fc386091] +description = "more than a single zero is valid" + +[ab56fa80-5de8-4735-8a4a-14dae588663e] +description = "input digit 9 is correctly converted to output digit 9" + +[b9887ee8-8337-46c5-bc45-3bcab51bc36f] +description = "very long input is valid" + +[8a7c0e24-85ea-4154-9cf1-c2db90eabc08] +description = "valid luhn with an odd number of digits and non zero first digit" + +[39a06a5a-5bad-4e0f-b215-b042d46209b1] +description = "using ascii value for non-doubled non-digit isn't allowed" + +[f94cf191-a62f-4868-bc72-7253114aa157] +description = "using ascii value for doubled non-digit isn't allowed" + +[8b72ad26-c8be-49a2-b99c-bcc3bf631b33] +description = "non-numeric, non-space char in the middle with a sum that's divisible by 10 isn't allowed" diff --git a/exercises/practice/luhn/src/luhn.art b/exercises/practice/luhn/src/luhn.art new file mode 100644 index 0000000..f4c472c --- /dev/null +++ b/exercises/practice/luhn/src/luhn.art @@ -0,0 +1,3 @@ +luhn?: function [value][ + panic "Please implement the luhn? function" +] diff --git a/exercises/practice/luhn/tester.art b/exercises/practice/luhn/tester.art new file mode 100644 index 0000000..80f4a8f --- /dev/null +++ b/exercises/practice/luhn/tester.art @@ -0,0 +1,3 @@ +import {unitt}! + +runTests.failFast findTests "tests" diff --git a/exercises/practice/luhn/tests/test-luhn.art b/exercises/practice/luhn/tests/test-luhn.art new file mode 100644 index 0000000..cfa8e11 --- /dev/null +++ b/exercises/practice/luhn/tests/test-luhn.art @@ -0,0 +1,114 @@ +import {unitt}! +import {src/luhn}! + +suite "Luhn" [ + test "single digit strings can not be valid" [ + result: luhn? "1" + assert -> false = result + ] + + test.skip "a single zero is invalid" [ + result: luhn? "0" + assert -> false = result + ] + + test.skip "a simple valid SIN that remains valid if reversed" [ + result: luhn? "059" + assert -> true = result + ] + + test.skip "a simple valid SIN that becomes invalid if reversed" [ + result: luhn? "59" + assert -> true = result + ] + + test.skip "a valid Canadian SIN" [ + result: luhn? "055 444 285" + assert -> true = result + ] + + test.skip "invalid Canadian SIN" [ + result: luhn? "055 444 286" + assert -> false = result + ] + + test.skip "invalid credit card" [ + result: luhn? "8273 1232 7352 0569" + assert -> false = result + ] + + test.skip "invalid long number with an even remainder" [ + result: luhn? "1 2345 6789 1234 5678 9012" + assert -> false = result + ] + + test.skip "invalid long number with a remainder divisible by 5" [ + result: luhn? "1 2345 6789 1234 5678 9013" + assert -> false = result + ] + + test.skip "valid number with an even number of digits" [ + result: luhn? "095 245 88" + assert -> true = result + ] + + test.skip "valid number with an odd number of spaces" [ + result: luhn? "234 567 891 234" + assert -> true = result + ] + + test.skip "valid strings with a non-digit added at the end become invalid" [ + result: luhn? "059a" + assert -> false = result + ] + + test.skip "valid strings with punctuation included become invalid" [ + result: luhn? "055-444-285" + assert -> false = result + ] + + test.skip "valid strings with symbols included become invalid" [ + result: luhn? "055# 444$ 285" + assert -> false = result + ] + + test.skip "single zero with space is invalid" [ + result: luhn? " 0" + assert -> false = result + ] + + test.skip "more than a single zero is valid" [ + result: luhn? "0000 0" + assert -> true = result + ] + + test.skip "input digit 9 is correctly converted to output digit 9" [ + result: luhn? "091" + assert -> true = result + ] + + test.skip "very long input is valid" [ + result: luhn? "9999999999 9999999999 9999999999 9999999999" + assert -> true = result + ] + + test.skip "valid luhn with an odd number of digits and non zero first digit" [ + result: luhn? "109" + assert -> true = result + ] + + test.skip "using ascii value for non-doubled non-digit isn't allowed" [ + result: luhn? "055b 444 285" + assert -> false = result + ] + + test.skip "using ascii value for doubled non-digit isn't allowed" [ + result: luhn? ":9" + assert -> false = result + ] + + test.skip "non-numeric, non-space char in the middle with a sum that's divisible by 10 isn't allowed" [ + result: luhn? "59%59" + assert -> false = result + ] +] From 19dec69008acd4747cdb6e31159f0dbc8b7acbf8 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A1s=20B=20Nagy?= <20251272+BNAndras@users.noreply.github.com> Date: Sun, 15 Dec 2024 10:36:51 -0800 Subject: [PATCH 2/2] Remove leading newline --- exercises/practice/luhn/.meta/src/example.art | 1 - 1 file changed, 1 deletion(-) diff --git a/exercises/practice/luhn/.meta/src/example.art b/exercises/practice/luhn/.meta/src/example.art index 9893de1..a84931c 100644 --- a/exercises/practice/luhn/.meta/src/example.art +++ b/exercises/practice/luhn/.meta/src/example.art @@ -1,4 +1,3 @@ - luhn?: function [value][ cleaned: replace value " " "" if 2 > size cleaned -> return false