Add new practice exercise: all-your-base

config.json

@@ -194,6 +194,14 @@
         "prerequisites": [],
         "difficulty": 8
       },
+      {
+        "slug": "all-your-base",
+        "name": "All Your Base",
+        "uuid": "36b4c4c7-c5a1-4885-bf2e-2b77130ab23a",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 8
+      },
       {
         "slug": "anagram",
         "name": "Anagram",

exercises/practice/all-your-base/.docs/instructions.append.md

@@ -0,0 +1,33 @@
+# SQLite-specific instructions
+
+* The **digits** column contains a JSON-encoded list of integers.
+  Example:
+  ```json
+  [1,0,1,0,1,0]
+  ```
+* The **result** column should contain JSON-encoded data: an object with the digits as integers or a descripition of any errors.
+  Examples:
+  ```json
+  {"digits":[1,0,1,0,1,0]}
+  ```
+  or
+  ```json
+  {"error":"some error description"}
+  ```
+
+## Table Schema
+
+```sql
+CREATE TABLE IF NOT EXISTS "all-your-base" (
+  input_base  INTEGER NOT NULL,
+  digits      TEXT    NOT NULL, -- json array
+  output_base INTEGER NOT NULL,
+  result      TEXT              -- json object
+);
+```
+
+## JSON documentation
+
+[JSON Functions And Operators][json-docs]
+
+[json-docs]: https://www.sqlite.org/json1.htm

exercises/practice/all-your-base/.docs/instructions.md

@@ -0,0 +1,28 @@
+# Instructions
+
+Convert a sequence of digits in one base, representing a number, into a sequence of digits in another base, representing the same number.
+
+~~~~exercism/note
+Try to implement the conversion yourself.
+Do not use something else to perform the conversion for you.
+~~~~
+
+## About [Positional Notation][positional-notation]
+
+In positional notation, a number in base **b** can be understood as a linear combination of powers of **b**.
+
+The number 42, _in base 10_, means:
+
+`(4 × 10¹) + (2 × 10⁰)`
+
+The number 101010, _in base 2_, means:
+
+`(1 × 2⁵) + (0 × 2⁴) + (1 × 2³) + (0 × 2²) + (1 × 2¹) + (0 × 2⁰)`
+
+The number 1120, _in base 3_, means:
+
+`(1 × 3³) + (1 × 3²) + (2 × 3¹) + (0 × 3⁰)`
+
+_Yes. Those three numbers above are exactly the same. Congratulations!_
+
+[positional-notation]: https://en.wikipedia.org/wiki/Positional_notation

exercises/practice/all-your-base/.docs/introduction.md

@@ -0,0 +1,8 @@
+# Introduction
+
+You've just been hired as professor of mathematics.
+Your first week went well, but something is off in your second week.
+The problem is that every answer given by your students is wrong!
+Luckily, your math skills have allowed you to identify the problem: the student answers _are_ correct, but they're all in base 2 (binary)!
+Amazingly, it turns out that each week, the students use a different base.
+To help you quickly verify the student answers, you'll be building a tool to translate between bases.

exercises/practice/all-your-base/.meta/config.json

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+{
+  "authors": [
+    "jimmytty"
+  ],
+  "files": {
+    "solution": [
+      "all-your-base.sql"
+    ],
+    "test": [
+      "all-your-base_test.sql"
+    ],
+    "example": [
+      ".meta/example.sql"
+    ]
+  },
+  "blurb": "Convert a number, represented as a sequence of digits in one base, to any other base."
+}

exercises/practice/all-your-base/.meta/example.sql

@@ -0,0 +1,121 @@
+UPDATE "all-your-base"
+   SET result = JSON_OBJECT('error', 'input base must be >= 2')
+ WHERE input_base < 2
+   AND result ISNULL
+;
+UPDATE "all-your-base"
+   SET result = JSON_OBJECT('error', 'output base must be >= 2')
+ WHERE output_base < 2
+   AND result ISNULL
+;
+UPDATE "all-your-base"
+   SET result = JSON_OBJECT(
+     'error', 'all digits must satisfy 0 <= d < input base'
+   )
+ WHERE (
+   SELECT COUNT(*)
+     FROM (
+       SELECT input_base, j.VALUE AS digit
+         FROM JSON_EACH(digits) j
+     )
+    WHERE digit < 0 OR digit >= input_base
+ ) != 0
+   AND result ISNULL
+;
+
+UPDATE "all-your-base"
+   SET result = JSON_OBJECT('digits', JSON_ARRAY(0))
+ WHERE (
+   SELECT COUNT(v)
+     FROM (
+       SELECT j.VALUE v FROM JSON_EACH(digits) j
+     )
+    WHERE v != 0
+ ) = 0
+   AND result ISNULL
+       ;
+
+UPDATE "all-your-base"
+   SET result = JSON_OBJECT('digits', (
+     WITH RECURSIVE rcte (n, d) AS (
+       VALUES((
+         SELECT
+           CAST(SUM(digit * POW(input_base, row_number - 1)) AS INTEGER)
+           FROM (
+             SELECT row_number() over() AS row_number, *
+               FROM (
+                 SELECT j.VALUE AS digit
+                   FROM json_each(digits) j
+                  ORDER BY rowid DESC
+               )
+           )
+       ), -1)
+       UNION ALL
+       SELECT
+         CAST(n % pow(10, CAST(log10(n) AS INT)) AS INT),
+         CAST(n / pow(10, CAST(log10(n) AS INT)) AS INT)
+       FROM rcte
+       WHERE n != 0
+     )
+     SELECT JSON_GROUP_ARRAY(d) FROM rcte WHERE d > -1
+   ))
+ WHERE output_base = 10
+   AND result ISNULL
+       ;
+
+UPDATE "all-your-base"
+   SET result = JSON_OBJECT('digits', (
+     WITH RECURSIVE rcte (n, d) AS (
+       VALUES((
+         SELECT GROUP_CONCAT(j.VALUE, '') * 1
+           FROM JSON_EACH(digits) j
+       ), -1)
+       UNION ALL
+       SELECT n / output_base, n % output_base
+       FROM rcte
+       WHERE n > 0
+     )
+     SELECT JSON_GROUP_ARRAY(d)
+       FROM (
+         SELECT d
+           FROM rcte
+          WHERE d > -1
+          ORDER BY row_number() OVER () DESC
+       )
+   ))
+ WHERE input_base = 10
+   AND result ISNULL
+       ;
+
+UPDATE "all-your-base"
+   SET result = JSON_OBJECT('digits', (
+     WITH RECURSIVE rcte (n, d) AS (
+       VALUES((
+         SELECT
+           CAST(SUM(digit * POW(input_base, row_number - 1)) AS INTEGER)
+           FROM (
+             SELECT row_number() over() AS row_number, *
+               FROM (
+                 SELECT j.VALUE AS digit
+                   FROM json_each(digits) j
+                  ORDER BY rowid DESC
+               )
+           )
+       ), -1)
+       UNION ALL
+       SELECT n / output_base, n % output_base
+       FROM rcte
+       WHERE n > 0
+     )
+     SELECT JSON_GROUP_ARRAY(d)
+       FROM (
+         SELECT d
+           FROM rcte
+          WHERE d > -1
+          ORDER BY row_number() OVER () DESC
+       )
+   ))
+ WHERE input_base  != 10
+   AND output_base != 10
+   AND result ISNULL
+;

exercises/practice/all-your-base/.meta/tests.toml

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+# 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.
+
+[5ce422f9-7a4b-4f44-ad29-49c67cb32d2c]
+description = "single bit one to decimal"
+
+[0cc3fea8-bb79-46ac-a2ab-5a2c93051033]
+description = "binary to single decimal"
+
+[f12db0f9-0d3d-42c2-b3ba-e38cb375a2b8]
+description = "single decimal to binary"
+
+[2c45cf54-6da3-4748-9733-5a3c765d925b]
+description = "binary to multiple decimal"
+
+[65ddb8b4-8899-4fcc-8618-181b2cf0002d]
+description = "decimal to binary"
+
+[8d418419-02a7-4824-8b7a-352d33c6987e]
+description = "trinary to hexadecimal"
+
+[d3901c80-8190-41b9-bd86-38d988efa956]
+description = "hexadecimal to trinary"
+
+[5d42f85e-21ad-41bd-b9be-a3e8e4258bbf]
+description = "15-bit integer"
+
+[d68788f7-66dd-43f8-a543-f15b6d233f83]
+description = "empty list"
+
+[5e27e8da-5862-4c5f-b2a9-26c0382b6be7]
+description = "single zero"
+
+[2e1c2573-77e4-4b9c-8517-6c56c5bcfdf2]
+description = "multiple zeros"
+
+[3530cd9f-8d6d-43f5-bc6e-b30b1db9629b]
+description = "leading zeros"
+
+[a6b476a1-1901-4f2a-92c4-4d91917ae023]
+description = "input base is one"
+
+[e21a693a-7a69-450b-b393-27415c26a016]
+description = "input base is zero"
+
+[54a23be5-d99e-41cc-88e0-a650ffe5fcc2]
+description = "input base is negative"
+
+[9eccf60c-dcc9-407b-95d8-c37b8be56bb6]
+description = "negative digit"
+
+[232fa4a5-e761-4939-ba0c-ed046cd0676a]
+description = "invalid positive digit"
+
+[14238f95-45da-41dc-95ce-18f860b30ad3]
+description = "output base is one"
+
+[73dac367-da5c-4a37-95fe-c87fad0a4047]
+description = "output base is zero"
+
+[13f81f42-ff53-4e24-89d9-37603a48ebd9]
+description = "output base is negative"
+
+[0e6c895d-8a5d-4868-a345-309d094cfe8d]
+description = "both bases are negative"

exercises/practice/all-your-base/all-your-base.sql

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+-- Schema: CREATE TABLE IF NOT EXISTS "all-your-base" (
+--           input_base  INTEGER NOT NULL,
+--           digits      TEXT    NOT NULL,  -- json array
+--           output_base INTEGER NOT NULL,
+--           result      TEXT               -- json object
+--         );
+-- Task: update the all-your-base table and set the result based on converting
+--       digits from input_base to output_base.
+--       * the digits column contains a JSON-encoded list of integers.
+--       * the result column should contain JSON-encoded data: an
+--         object with the digits as integers or a descripition of any errors.

exercises/practice/all-your-base/all-your-base_test.sql

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+-- Create database:
+.read ./create_fixture.sql
+
+-- Read user student solution and save any output as markdown in user_output.md:
+.mode markdown
+.output user_output.md
+.read ./all-your-base.sql
+.output
+
+-- Create a clean testing environment:
+.read ./create_test_table.sql
+
+-- Comparison of user input and the tests updates the status for each test:
+UPDATE tests
+SET status = 'pass'
+FROM (SELECT input_base, digits, output_base, result FROM "all-your-base") AS actual
+WHERE (actual.input_base, actual.digits, actual.output_base, JSON(actual.result)) = (tests.input_base, tests.digits, tests.output_base, JSON(tests.expected));
+
+-- Update message for failed tests to give helpful information:
+UPDATE tests
+SET message = (
+    'Result for "'
+    || JSON_OBJECT(
+         'input_base',  tests.input_base,
+         'digits',      JSON(tests.digits),
+         'output_base', tests.output_base
+       )
+    || '"'
+    || ' is <' || COALESCE(actual.result, 'NULL')
+    || '> but should be <' || tests.expected || '>'
+)
+FROM (SELECT input_base, digits, output_base, result FROM "all-your-base") AS actual
+WHERE (actual.input_base, actual.digits, actual.output_base) = (tests.input_base, tests.digits, tests.output_base) AND tests.status = 'fail';
+
+-- Save results to ./output.json (needed by the online test-runner)
+.mode json
+.once './output.json'
+SELECT description, status, message, output, test_code, task_id
+FROM tests;
+
+-- Display test results in readable form for the student:
+.mode table
+SELECT description, status, message
+FROM tests;

exercises/practice/all-your-base/create_fixture.sql

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+DROP TABLE IF EXISTS "all-your-base";
+CREATE TABLE "all-your-base" (
+  input_base  INTEGER NOT NULL,
+  digits      TEXT    NOT NULL, -- json array
+  output_base INTEGER NOT NULL,
+  result      TEXT              -- json object
+);
+
+.mode csv
+.import ./data.csv "all-your-base"
+
+UPDATE "all-your-base" SET result = NULL;