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Add practice exercise: largest-series-product (#191)
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‎config.json

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"prerequisites": [],
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"difficulty": 8
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},
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{
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"slug": "largest-series-product",
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"name": "Largest Series Product",
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"uuid": "66555259-8a28-428a-bca8-c0b06c889297",
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"practices": [],
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"prerequisites": [],
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"difficulty": 8
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},
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{
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"slug": "luhn",
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"name": "Luhn",
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"practices": [],
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"prerequisites": [],
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"difficulty": 8
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},
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},
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{
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"slug": "saddle-points",
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"name": "Saddle Points",
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"uuid": "d050e56b-9f86-416c-baa3-10a98f47b944",
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"slug": "run-length-encoding",
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"name": "Run-Length Encoding",
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"uuid": "065feae7-f6fc-46b9-a226-d3d9df9d192b",
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"practices": [],
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"prerequisites": [],
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"difficulty": 8
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},
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{
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"slug": "run-length-encoding",
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"name": "Run-Length Encoding",
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"uuid": "065feae7-f6fc-46b9-a226-d3d9df9d192b",
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"slug": "saddle-points",
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"name": "Saddle Points",
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"uuid": "d050e56b-9f86-416c-baa3-10a98f47b944",
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"practices": [],
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"prerequisites": [],
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"difficulty": 8

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

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# Instructions
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Your task is to look for patterns in the long sequence of digits in the encrypted signal.
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The technique you're going to use here is called the largest series product.
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Let's define a few terms, first.
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- **input**: the sequence of digits that you need to analyze
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- **series**: a sequence of adjacent digits (those that are next to each other) that is contained within the input
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- **span**: how many digits long each series is
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- **product**: what you get when you multiply numbers together
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Let's work through an example, with the input `"63915"`.
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- To form a series, take adjacent digits in the original input.
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- If you are working with a span of `3`, there will be three possible series:
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- `"639"`
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- `"391"`
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- `"915"`
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- Then we need to calculate the product of each series:
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- The product of the series `"639"` is 162 (`6 × 3 × 9 = 162`)
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- The product of the series `"391"` is 27 (`3 × 9 × 1 = 27`)
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- The product of the series `"915"` is 45 (`9 × 1 × 5 = 45`)
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- 162 is bigger than both 27 and 45, so the largest series product of `"63915"` is from the series `"639"`.
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So the answer is **162**.

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

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# Introduction
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You work for a government agency that has intercepted a series of encrypted communication signals from a group of bank robbers.
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The signals contain a long sequence of digits.
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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

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{
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"authors": [
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"jimmytty"
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],
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"files": {
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"solution": [
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"largest-series-product.sql"
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],
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"test": [
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"largest-series-product_test.sql"
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],
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"example": [
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".meta/example.sql"
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]
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},
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"blurb": "Given a string of digits, calculate the largest product for a contiguous substring of digits of length n.",
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"source": "A variation on Problem 8 at Project Euler",
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"source_url": "https://projecteuler.net/problem=8"
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}

‎exercises/practice/largest-series-product/.meta/example.sql

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UPDATE "largest-series-product"
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SET error = 'span must not exceed string length'
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WHERE LENGTH(digits) < span
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;
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UPDATE "largest-series-product"
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SET error = 'digits input must only contain digits'
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WHERE GLOB('*[^0-9]*', digits)
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;
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UPDATE "largest-series-product"
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SET error = 'span must not be negative'
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WHERE span < 0
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;
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UPDATE "largest-series-product"
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SET result = 1
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WHERE span = 0
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;
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UPDATE "largest-series-product"
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SET result = (
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WITH RECURSIVE split_series (string, serie, product) AS (
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VALUES (digits, NULL, NULL)
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UNION ALL
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SELECT SUBSTR(string, 2),
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SUBSTR(string, 1, span),
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(WITH RECURSIVE split_digits (serie, digit) AS (
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VALUES (SUBSTR(string, 1, span), NULL)
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UNION ALL
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SELECT SUBSTR(serie, 2), SUBSTR(serie, 1, 1) * 1
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FROM split_digits
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WHERE serie <> ''
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)
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SELECT IIF(
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(SELECT 1 FROM split_digits WHERE digit = 0),
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0, EXP(SUM(LN(digit)))) AS product
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FROM split_digits
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WHERE digit NOTNULL
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)
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FROM split_series
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WHERE string <> ''
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)
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SELECT ROUND(MAX(product)) FROM split_series WHERE LENGTH(serie) = span
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)
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WHERE error ISNULL
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AND result ISNULL
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;

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

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# This is an auto-generated file.
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#
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# Regenerating this file via `configlet sync` will:
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# - Recreate every `description` key/value pair
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# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
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# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
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# - Preserve any other key/value pair
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#
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# As user-added comments (using the # character) will be removed when this file
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# is regenerated, comments can be added via a `comment` key.
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[7c82f8b7-e347-48ee-8a22-f672323324d4]
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description = "finds the largest product if span equals length"
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[88523f65-21ba-4458-a76a-b4aaf6e4cb5e]
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description = "can find the largest product of 2 with numbers in order"
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[f1376b48-1157-419d-92c2-1d7e36a70b8a]
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description = "can find the largest product of 2"
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[46356a67-7e02-489e-8fea-321c2fa7b4a4]
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description = "can find the largest product of 3 with numbers in order"
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[a2dcb54b-2b8f-4993-92dd-5ce56dece64a]
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description = "can find the largest product of 3"
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[673210a3-33cd-4708-940b-c482d7a88f9d]
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description = "can find the largest product of 5 with numbers in order"
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[02acd5a6-3bbf-46df-8282-8b313a80a7c9]
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description = "can get the largest product of a big number"
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[76dcc407-21e9-424c-a98e-609f269622b5]
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description = "reports zero if the only digits are zero"
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[6ef0df9f-52d4-4a5d-b210-f6fae5f20e19]
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description = "reports zero if all spans include zero"
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[5d81aaf7-4f67-4125-bf33-11493cc7eab7]
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description = "rejects span longer than string length"
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include = false
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[0ae1ce53-d9ba-41bb-827f-2fceb64f058b]
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description = "rejects span longer than string length"
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reimplements = "5d81aaf7-4f67-4125-bf33-11493cc7eab7"
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[06bc8b90-0c51-4c54-ac22-3ec3893a079e]
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description = "reports 1 for empty string and empty product (0 span)"
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[3ec0d92e-f2e2-4090-a380-70afee02f4c0]
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description = "reports 1 for nonempty string and empty product (0 span)"
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[6d96c691-4374-4404-80ee-2ea8f3613dd4]
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description = "rejects empty string and nonzero span"
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include = false
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[6cf66098-a6af-4223-aab1-26aeeefc7402]
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description = "rejects empty string and nonzero span"
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reimplements = "6d96c691-4374-4404-80ee-2ea8f3613dd4"
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[7a38f2d6-3c35-45f6-8d6f-12e6e32d4d74]
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description = "rejects invalid character in digits"
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[5fe3c0e5-a945-49f2-b584-f0814b4dd1ef]
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description = "rejects negative span"
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include = false
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[c859f34a-9bfe-4897-9c2f-6d7f8598e7f0]
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description = "rejects negative span"
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reimplements = "5fe3c0e5-a945-49f2-b584-f0814b4dd1ef"

‎exercises/practice/largest-series-product/create_fixture.sql

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DROP TABLE IF EXISTS "largest-series-product";
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CREATE TABLE "largest-series-product" (
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digits TEXT NOT NULL,
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span INTEGER NOT NULL,
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result INTEGER ,
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error TEXT
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);
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.mode csv
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.import ./data.csv "largest-series-product"
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UPDATE "largest-series-product" SET result = NULL, error = NULL;

‎exercises/practice/largest-series-product/create_test_table.sql

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DROP TABLE IF EXISTS tests;
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CREATE TABLE IF NOT EXISTS tests (
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-- uuid and description are taken from the test.toml file
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uuid TEXT PRIMARY KEY,
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description TEXT NOT NULL,
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-- The following section is needed by the online test-runner
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status TEXT DEFAULT 'fail',
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message TEXT,
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output TEXT,
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test_code TEXT,
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task_id INTEGER DEFAULT NULL,
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-- Here are columns for the actual tests
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digits TEXT NOT NULL,
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span INTEGER NOT NULL,
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expected_result INTEGER,
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expected_error TEXT
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);
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INSERT INTO tests (uuid, description, digits, span, expected_result, expected_error)
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VALUES
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('7c82f8b7-e347-48ee-8a22-f672323324d4', 'finds the largest product if span equals length', '29', 2, 18, NULL),
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('88523f65-21ba-4458-a76a-b4aaf6e4cb5e', 'can find the largest product of 2 with numbers in order', '0123456789', 2, 72, NULL),
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('f1376b48-1157-419d-92c2-1d7e36a70b8a', 'can find the largest product of 2', '576802143', 2, 48, NULL),
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('46356a67-7e02-489e-8fea-321c2fa7b4a4', 'can find the largest product of 3 with numbers in order', '0123456789', 3, 504, NULL),
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('a2dcb54b-2b8f-4993-92dd-5ce56dece64a', 'can find the largest product of 3', '1027839564', 3, 270, NULL),
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('673210a3-33cd-4708-940b-c482d7a88f9d', 'can find the largest product of 5 with numbers in order', '0123456789', 5, 15120, NULL),
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('02acd5a6-3bbf-46df-8282-8b313a80a7c9', 'can get the largest product of a big number', '73167176531330624919225119674426574742355349194934', 6, 23520, NULL),
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('76dcc407-21e9-424c-a98e-609f269622b5', 'reports zero if the only digits are zero', '0000', 2, 0, NULL),
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('6ef0df9f-52d4-4a5d-b210-f6fae5f20e19', 'reports zero if all spans include zero', '99099', 3, 0, NULL),
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('0ae1ce53-d9ba-41bb-827f-2fceb64f058b', 'rejects span longer than string length', '123', 4, NULL, 'span must not exceed string length'),
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('06bc8b90-0c51-4c54-ac22-3ec3893a079e', 'reports 1 for empty string and empty product (0 span)', '', 0, 1, NULL),
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('3ec0d92e-f2e2-4090-a380-70afee02f4c0', 'reports 1 for nonempty string and empty product (0 span)', '123', 0, 1, NULL),
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('6cf66098-a6af-4223-aab1-26aeeefc7402', 'rejects empty string and nonzero span', '', 1, NULL, 'span must not exceed string length'),
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('7a38f2d6-3c35-45f6-8d6f-12e6e32d4d74', 'rejects invalid character in digits', '1234a5', 2, NULL, 'digits input must only contain digits'),
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('c859f34a-9bfe-4897-9c2f-6d7f8598e7f0', 'rejects negative span', '12345', -1, NULL, 'span must not be negative');

‎exercises/practice/largest-series-product/data.csv

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"29",2,,
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"0123456789",2,,
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"576802143",2,,
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"0123456789",3,,
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"1027839564",3,,
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"0123456789",5,,
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"73167176531330624919225119674426574742355349194934",6,,
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"0000",2,,
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"99099",3,,
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"123",4,,
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"",0,,
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"123",0,,
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"",1,,
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"1234a5",2,,
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"12345",-1,,

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

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-- Schema:
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-- CREATE TABLE "largest-series-product" (
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-- digits TEXT NOT NULL,
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-- span INTEGER NOT NULL,
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-- result INTEGER ,
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-- error TEXT
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-- );
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--
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-- Task: update the largest-series-product table and set the result or the error columns bases on the digits and the span.

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