Add largest-series-product

config.json

@@ -462,6 +462,14 @@
         "prerequisites": [],
         "difficulty": 3
       },
+      {
+        "slug": "largest-series-product",
+        "name": "Largest Series Product",
+        "uuid": "e3d2e2d5-bd70-42b8-8d61-871af9b16679",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 3
+      },
       {
         "slug": "custom-set",
         "name": "Custom Set",

exercises/practice/largest-series-product/.docs/instructions.md

@@ -0,0 +1,26 @@
+# Instructions
+
+Your task is to look for patterns in the long sequence of digits in the encrypted signal.
+
+The technique you're going to use here is called the largest series product.
+
+Let's define a few terms, first.
+
+- **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
+
+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**.

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.

exercises/practice/largest-series-product/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "glennj"
+  ],
+  "files": {
+    "solution": [
+      "largest-series-product.wren"
+    ],
+    "test": [
+      "largest-series-product.spec.wren"
+    ],
+    "example": [
+      ".meta/proof.ci.wren"
+    ]
+  },
+  "blurb": "Given a string of digits, calculate the largest product for a contiguous substring of digits of length n.",
+  "source": "A variation on Problem 8 at Project Euler",
+  "source_url": "https://projecteuler.net/problem=8"
+}

exercises/practice/largest-series-product/.meta/proof.ci.wren

@@ -0,0 +1,25 @@
+class Series {
+  construct new(series, span) {
+    _span = span
+    _digits = series.codePoints.map {|cp| cp - 48}.toList
+
+    if (_span < 0) {
+      Fiber.abort("span must not be negative")
+    }
+    if (_span > series.count) {
+      Fiber.abort("span must be smaller than string length")
+    }
+    if (_digits.any {|d| d < 0 || d > 9}) {
+      Fiber.abort("digits input must only contain digits")
+    }
+  }
+
+  largestProduct {
+    var indices = 0..(_digits.count - _span)
+    var products = indices.map {|i| product_(_digits[i...(i + _span)])}
+    return max_(products)
+  }
+
+  product_(list) { list.reduce(1) {|prod, num| prod * num} }
+  max_(list) { list.reduce(0) {|max, prod| max.max(prod)} }
+}

exercises/practice/largest-series-product/.meta/tests.toml

@@ -0,0 +1,60 @@
+# 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.
+
+[7c82f8b7-e347-48ee-8a22-f672323324d4]
+description = "finds the largest product if span equals length"
+
+[88523f65-21ba-4458-a76a-b4aaf6e4cb5e]
+description = "can find the largest product of 2 with numbers in order"
+
+[f1376b48-1157-419d-92c2-1d7e36a70b8a]
+description = "can find the largest product of 2"
+
+[46356a67-7e02-489e-8fea-321c2fa7b4a4]
+description = "can find the largest product of 3 with numbers in order"
+
+[a2dcb54b-2b8f-4993-92dd-5ce56dece64a]
+description = "can find the largest product of 3"
+
+[673210a3-33cd-4708-940b-c482d7a88f9d]
+description = "can find the largest product of 5 with numbers in order"
+
+[02acd5a6-3bbf-46df-8282-8b313a80a7c9]
+description = "can get the largest product of a big number"
+
+[76dcc407-21e9-424c-a98e-609f269622b5]
+description = "reports zero if the only digits are zero"
+
+[6ef0df9f-52d4-4a5d-b210-f6fae5f20e19]
+description = "reports zero if all spans include zero"
+
+[5d81aaf7-4f67-4125-bf33-11493cc7eab7]
+description = "rejects span longer than string length"
+
+[06bc8b90-0c51-4c54-ac22-3ec3893a079e]
+description = "reports 1 for empty string and empty product (0 span)"
+
+[3ec0d92e-f2e2-4090-a380-70afee02f4c0]
+description = "reports 1 for nonempty string and empty product (0 span)"
+
+[6d96c691-4374-4404-80ee-2ea8f3613dd4]
+description = "rejects empty string and nonzero span"
+
+[7a38f2d6-3c35-45f6-8d6f-12e6e32d4d74]
+description = "rejects invalid character in digits"
+
+[5fe3c0e5-a945-49f2-b584-f0814b4dd1ef]
+description = "rejects negative span"
+include = false
+
+[c859f34a-9bfe-4897-9c2f-6d7f8598e7f0]
+description = "rejects negative span"
+reimplements = "5fe3c0e5-a945-49f2-b584-f0814b4dd1ef"

exercises/practice/largest-series-product/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2024 Exercism
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

exercises/practice/largest-series-product/largest-series-product.spec.wren

@@ -0,0 +1,95 @@
+import "./largest-series-product" for Series
+import "wren-testie/testie" for Testie, Expect
+
+Testie.test("LargestSeriesProduct") { |do, skip|
+
+  do.test("finds the largest product if span equals length") {
+    var actual = Series.new("29", 2).largestProduct
+    var expected = 18
+    Expect.value(actual).toEqual(expected)
+  }
+
+  skip.test("can find the largest product of 2 with numbers in order") {
+    var actual = Series.new("0123456789", 2).largestProduct
+    var expected = 72
+    Expect.value(actual).toEqual(expected)
+  }
+
+  skip.test("can find the largest product of 2") {
+    var actual = Series.new("576802143", 2).largestProduct
+    var expected = 48
+    Expect.value(actual).toEqual(expected)
+  }
+
+  skip.test("can find the largest product of 3 with numbers in order") {
+    var actual = Series.new("0123456789", 3).largestProduct
+    var expected = 504
+    Expect.value(actual).toEqual(expected)
+  }
+
+  skip.test("can find the largest product of 3") {
+    var actual = Series.new("1027839564", 3).largestProduct
+    var expected = 270
+    Expect.value(actual).toEqual(expected)
+  }
+
+  skip.test("can find the largest product of 5 with numbers in order") {
+    var actual = Series.new("0123456789", 5).largestProduct
+    var expected = 15120
+    Expect.value(actual).toEqual(expected)
+  }
+
+  skip.test("can get the largest product of a big number") {
+    var actual = Series.new("73167176531330624919225119674426574742355349194934", 6).largestProduct
+    var expected = 23520
+    Expect.value(actual).toEqual(expected)
+  }
+
+  skip.test("reports zero if the only digits are zero") {
+    var actual = Series.new("0000", 2).largestProduct
+    var expected = 0
+    Expect.value(actual).toEqual(expected)
+  }
+
+  skip.test("reports zero if all spans include zero") {
+    var actual = Series.new("99099", 3).largestProduct
+    var expected = 0
+    Expect.value(actual).toEqual(expected)
+  }
+
+  skip.test("rejects span longer than string length") {
+    Expect.that {
+      Series.new("123", 4).largestProduct
+    }.abortsWith("span must be smaller than string length")
+  }
+
+  skip.test("reports 1 for empty string and empty product (0 span)") {
+    var actual = Series.new("", 0).largestProduct
+    var expected = 1
+    Expect.value(actual).toEqual(expected)
+  }
+
+  skip.test("reports 1 for nonempty string and empty product (0 span)") {
+    var actual = Series.new("123", 0).largestProduct
+    var expected = 1
+    Expect.value(actual).toEqual(expected)
+  }
+
+  skip.test("rejects empty string and nonzero span") {
+    Expect.that {
+      Series.new("", 1).largestProduct
+    }.abortsWith("span must be smaller than string length")
+  }
+
+  skip.test("rejects invalid character in digits") {
+    Expect.that {
+      Series.new("1234a5", 2).largestProduct
+    }.abortsWith("digits input must only contain digits")
+  }
+
+  skip.test("rejects negative span") {
+    Expect.that {
+      Series.new("12345", -1).largestProduct
+    }.abortsWith("span must not be negative")
+  }
+}

exercises/practice/largest-series-product/largest-series-product.wren

@@ -0,0 +1,5 @@
+class Series {
+  construct new() {
+    Fiber.abort("Remove this statement and implement this function")
+  }
+}

exercises/practice/largest-series-product/package.wren

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+import "wren-package" for WrenPackage, Dependency
+import "os" for Process
+
+class Package is WrenPackage {
+  construct new() {}
+  name { "exercism/largest-series-product" }
+  dependencies {
+    return [
+      Dependency.new("wren-testie", "0.3.0", "https://github.com/joshgoebel/wren-testie.git")
+    ]
+  }
+}
+
+Package.new().default()