From 38b792762db157c2999b3ef205fe7ae7b280c397 Mon Sep 17 00:00:00 2001 From: Katrina Owen Date: Wed, 12 Apr 2023 11:34:42 +0200 Subject: [PATCH 1/2] Sync largest-series-product docs with problem-specifications The largest-series-product exercise has been overhauled as part of a project to make practice exercises more consistent and friendly. For more context, please see the discussion in the forum, as well as the pull request that updated the exercise in the problem-specifications repository: - https://forum.exercism.org/t/new-project-making-practice-exercises-more-consistent-and-human-across-exercism/3943 - https://github.com/exercism/problem-specifications/pull/2246 --- .../.docs/instructions.md | 32 ++++++++++++------- .../.docs/introduction.md | 5 +++ 2 files changed, 25 insertions(+), 12 deletions(-) create mode 100644 exercises/practice/largest-series-product/.docs/introduction.md diff --git a/exercises/practice/largest-series-product/.docs/instructions.md b/exercises/practice/largest-series-product/.docs/instructions.md index 5a3c18de5..f297b57f7 100644 --- a/exercises/practice/largest-series-product/.docs/instructions.md +++ b/exercises/practice/largest-series-product/.docs/instructions.md @@ -1,18 +1,26 @@ # Instructions -Given a string of digits, calculate the largest product for a contiguous -substring of digits of length n. +Your task is to look for patterns in the long sequence of digits in the encrypted signal. -For example, for the input `'1027839564'`, the largest product for a -series of 3 digits is 270 (9 \* 5 \* 6), and the largest product for a -series of 5 digits is 7560 (7 \* 8 \* 3 \* 9 \* 5). +The technique you're going to use here is called the largest series product. -Note that these series are only required to occupy *adjacent positions* -in the input; the digits need not be *numerically consecutive*. +Let's define a few terms, first. -For the input `'73167176531330624919225119674426574742355349194934'`, -the largest product for a series of 6 digits is 23520. +- **input**: the sequence of digits that you need to analyze +- **series**: a sequence of adjacent digits (those that are next to each other) that is contained within the input +- **span**: how many digits long each series is +- **product**: what you get when you multiply numbers together -For a series of zero digits, the largest product is 1 because 1 is the multiplicative identity. -(You don't need to know what a multiplicative identity is to solve this problem; -it just means that multiplying a number by 1 gives you the same number.) +Let's work through an example, with the input `"63915"`. + +- To form a series, take adjacent digits in the original input. +- If you are working with a span of `3`, there will be three possible series: + - `"639"` + - `"391"` + - `"915"` +- Then we need to calculate the product of each series: + - The product of the series `"639"` is 162 (`6 × 3 × 9 = 162`) + - The product of the series `"391"` is 27 (`3 × 9 × 1 = 27`) + - The product of the series `"915"` is 45 (`9 × 1 × 5 = 45`) +- 162 is bigger than both 27 and 45, so the largest series product of `"63915"` is from the series `"639"`. + So the answer is **162**. diff --git a/exercises/practice/largest-series-product/.docs/introduction.md b/exercises/practice/largest-series-product/.docs/introduction.md new file mode 100644 index 000000000..597bb5fa1 --- /dev/null +++ b/exercises/practice/largest-series-product/.docs/introduction.md @@ -0,0 +1,5 @@ +# Introduction + +You work for a government agency that has intercepted a series of encrypted communication signals from a group of bank robbers. +The signals contain a long sequence of digits. +Your team needs to use various digital signal processing techniques to analyze the signals and identify any patterns that may indicate the planning of a heist. From ec3acaef962cebf7be68545be76be2a1add1e99f Mon Sep 17 00:00:00 2001 From: Katrina Owen Date: Wed, 12 Apr 2023 11:34:55 +0200 Subject: [PATCH 2/2] Delete test cases from largest-series-product This deletes two deprecated test cases so that we can dramatically simplify the instructions for this exercise. --- .../practice/largest-series-product/.meta/tests.toml | 2 ++ .../LargestSeriesProductTests.fs | 12 ------------ 2 files changed, 2 insertions(+), 12 deletions(-) diff --git a/exercises/practice/largest-series-product/.meta/tests.toml b/exercises/practice/largest-series-product/.meta/tests.toml index 6c111adf0..883169259 100644 --- a/exercises/practice/largest-series-product/.meta/tests.toml +++ b/exercises/practice/largest-series-product/.meta/tests.toml @@ -41,9 +41,11 @@ description = "rejects span longer than string length" [06bc8b90-0c51-4c54-ac22-3ec3893a079e] description = "reports 1 for empty string and empty product (0 span)" +include = false [3ec0d92e-f2e2-4090-a380-70afee02f4c0] description = "reports 1 for nonempty string and empty product (0 span)" +include = false [6d96c691-4374-4404-80ee-2ea8f3613dd4] description = "rejects empty string and nonzero span" diff --git a/exercises/practice/largest-series-product/LargestSeriesProductTests.fs b/exercises/practice/largest-series-product/LargestSeriesProductTests.fs index 1dce93228..a099ac802 100644 --- a/exercises/practice/largest-series-product/LargestSeriesProductTests.fs +++ b/exercises/practice/largest-series-product/LargestSeriesProductTests.fs @@ -65,18 +65,6 @@ let ``Rejects span longer than string length`` () = let span = 4 largestProduct digits span |> should equal None -[] -let ``Reports 1 for empty string and empty product (0 span)`` () = - let digits = "" - let span = 0 - largestProduct digits span |> should equal (Some 1) - -[] -let ``Reports 1 for nonempty string and empty product (0 span)`` () = - let digits = "123" - let span = 0 - largestProduct digits span |> should equal (Some 1) - [] let ``Rejects empty string and nonzero span`` () = let digits = ""