Sync docs and metadata

exercises/practice/accumulate/.meta/config.json

@@ -21,5 +21,5 @@
   },
   "blurb": "Implement the `accumulate` operation, which, given a collection and an operation to perform on each element of the collection, returns a new collection containing the result of applying that operation to each element of the input collection.",
   "source": "Conversation with James Edward Gray II",
-  "source_url": "https://twitter.com/jeg2"
+  "source_url": "http://graysoftinc.com/"
 }

exercises/practice/acronym/.docs/instructions.md

@@ -10,8 +10,8 @@ Punctuation is handled as follows: hyphens are word separators (like whitespace)
 
 For example:
 
-|Input|Output|
-|-|-|
-|As Soon As Possible|ASAP|
-|Liquid-crystal display|LCD|
-|Thank George It's Friday!|TGIF|
+| Input                     | Output |
+| ------------------------- | ------ |
+| As Soon As Possible       | ASAP   |
+| Liquid-crystal display    | LCD    |
+| Thank George It's Friday! | TGIF   |

exercises/practice/affine-cipher/.docs/instructions.md

@@ -6,7 +6,7 @@ The affine cipher is a type of monoalphabetic substitution cipher.
 Each character is mapped to its numeric equivalent, encrypted with a mathematical function and then converted to the letter relating to its new numeric value.
 Although all monoalphabetic ciphers are weak, the affine cipher is much stronger than the atbash cipher, because it has many more keys.
 
-[//]: # ( monoalphabetic as spelled by Merriam-Webster, compare to polyalphabetic )
+[//]: # " monoalphabetic as spelled by Merriam-Webster, compare to polyalphabetic "
 
 ## Encryption
 
@@ -23,7 +23,7 @@ Where:
   For the Roman alphabet `m` is `26`.
 - `a` and `b` are integers which make the encryption key
 
-Values `a` and `m` must be *coprime* (or, *relatively prime*) for automatic decryption to succeed, i.e., they have number `1` as their only common factor (more information can be found in the [Wikipedia article about coprime integers][coprime-integers]).
+Values `a` and `m` must be _coprime_ (or, _relatively prime_) for automatic decryption to succeed, i.e., they have number `1` as their only common factor (more information can be found in the [Wikipedia article about coprime integers][coprime-integers]).
 In case `a` is not coprime to `m`, your program should indicate that this is an error.
 Otherwise it should encrypt or decrypt with the provided key.
 

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

@@ -14,20 +14,20 @@ Given a number in base **a**, represented as a sequence of digits, convert it to
 
 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:
+The number 42, _in base 10_, means:
 
 `(4 * 10^1) + (2 * 10^0)`
 
-The number 101010, *in base 2*, means:
+The number 101010, _in base 2_, means:
 
 `(1 * 2^5) + (0 * 2^4) + (1 * 2^3) + (0 * 2^2) + (1 * 2^1) + (0 * 2^0)`
 
-The number 1120, *in base 3*, means:
+The number 1120, _in base 3_, means:
 
 `(1 * 3^3) + (1 * 3^2) + (2 * 3^1) + (0 * 3^0)`
 
 I think you got the idea!
 
-*Yes. Those three numbers above are exactly the same. Congratulations!*
+_Yes. Those three numbers above are exactly the same. Congratulations!_
 
 [positional-notation]: https://en.wikipedia.org/wiki/Positional_notation

exercises/practice/allergies/.docs/instructions.md

@@ -22,6 +22,6 @@ Now, given just that score of 34, your program should be able to say:
 - Whether Tom is allergic to any one of those allergens listed above.
 - All the allergens Tom is allergic to.
 
-Note: a given score may include allergens **not** listed above (i.e.  allergens that score 256, 512, 1024, etc.).
+Note: a given score may include allergens **not** listed above (i.e. allergens that score 256, 512, 1024, etc.).
 Your program should ignore those components of the score.
 For example, if the allergy score is 257, your program should only report the eggs (1) allergy.

exercises/practice/armstrong-numbers/.docs/instructions.md

@@ -5,9 +5,9 @@ An [Armstrong number][armstrong-number] is a number that is the sum of its own d
 For example:
 
 - 9 is an Armstrong number, because `9 = 9^1 = 9`
-- 10 is *not* an Armstrong number, because `10 != 1^2 + 0^2 = 1`
+- 10 is _not_ an Armstrong number, because `10 != 1^2 + 0^2 = 1`
 - 153 is an Armstrong number, because: `153 = 1^3 + 5^3 + 3^3 = 1 + 125 + 27 = 153`
-- 154 is *not* an Armstrong number, because: `154 != 1^3 + 5^3 + 4^3 = 1 + 125 + 64 = 190`
+- 154 is _not_ an Armstrong number, because: `154 != 1^3 + 5^3 + 4^3 = 1 + 125 + 64 = 190`
 
 Write some code to determine whether a number is an Armstrong number.
 

exercises/practice/binary-search-tree/.meta/config.json

@@ -14,6 +14,5 @@
     ]
   },
   "blurb": "Insert and search for numbers in a binary tree.",
-  "source": "Josh Cheek",
-  "source_url": "https://twitter.com/josh_cheek"
+  "source": "Josh Cheek"
 }

exercises/practice/binary-search/.docs/instructions.md

@@ -11,7 +11,7 @@ Binary search only works when a list has been sorted.
 
 The algorithm looks like this:
 
-- Find the middle element of a *sorted* list and compare it with the item we're looking for.
+- Find the middle element of a _sorted_ list and compare it with the item we're looking for.
 - If the middle element is our item, then we're done!
 - If the middle element is greater than our item, we can eliminate that element and all the elements **after** it.
 - If the middle element is less than our item, we can eliminate that element and all the elements **before** it.

exercises/practice/book-store/.docs/instructions.md

@@ -36,8 +36,8 @@ This would give a total of:
 
 Resulting in:
 
-- 5 × (100% - 25%) * $8 = 5 × $6.00 = $30.00, plus
-- 3 × (100% - 10%) * $8 = 3 × $7.20 = $21.60
+- 5 × (100% - 25%) × $8 = 5 × $6.00 = $30.00, plus
+- 3 × (100% - 10%) × $8 = 3 × $7.20 = $21.60
 
 Which equals $51.60.
 
@@ -53,8 +53,8 @@ This would give a total of:
 
 Resulting in:
 
-- 4 × (100% - 20%) * $8 = 4 × $6.40 = $25.60, plus
-- 4 × (100% - 20%) * $8 = 4 × $6.40 = $25.60
+- 4 × (100% - 20%) × $8 = 4 × $6.40 = $25.60, plus
+- 4 × (100% - 20%) × $8 = 4 × $6.40 = $25.60
 
 Which equals $51.20.
 

exercises/practice/clock/.meta/config.json

@@ -17,6 +17,5 @@
     ]
   },
   "blurb": "Implement a clock that handles times without dates.",
-  "source": "Pairing session with Erin Drummond",
-  "source_url": "https://twitter.com/ebdrummond"
+  "source": "Pairing session with Erin Drummond"
 }

exercises/practice/diamond/.docs/instructions.md

@@ -1,22 +1,21 @@
 # Instructions
 
-The diamond kata takes as its input a letter, and outputs it in a diamond
-shape. Given a letter, it prints a diamond starting with 'A', with the
-supplied letter at the widest point.
+The diamond kata takes as its input a letter, and outputs it in a diamond shape.
+Given a letter, it prints a diamond starting with 'A', with the supplied letter at the widest point.
 
 ## Requirements
 
-* The first row contains one 'A'.
-* The last row contains one 'A'.
-* All rows, except the first and last, have exactly two identical letters.
-* All rows have as many trailing spaces as leading spaces. (This might be 0).
-* The diamond is horizontally symmetric.
-* The diamond is vertically symmetric.
-* The diamond has a square shape (width equals height).
-* The letters form a diamond shape.
-* The top half has the letters in ascending order.
-* The bottom half has the letters in descending order.
-* The four corners (containing the spaces) are triangles.
+- The first row contains one 'A'.
+- The last row contains one 'A'.
+- All rows, except the first and last, have exactly two identical letters.
+- All rows have as many trailing spaces as leading spaces. (This might be 0).
+- The diamond is horizontally symmetric.
+- The diamond is vertically symmetric.
+- The diamond has a square shape (width equals height).
+- The letters form a diamond shape.
+- The top half has the letters in ascending order.
+- The bottom half has the letters in descending order.
+- The four corners (containing the spaces) are triangles.
 
 ## Examples
 

exercises/practice/diamond/.meta/config.json

@@ -1,6 +1,10 @@
 {
-  "authors": ["m-dango"],
-  "contributors": ["util"],
+  "authors": [
+    "m-dango"
+  ],
+  "contributors": [
+    "util"
+  ],
   "files": {
     "solution": [
       "Diamond.rakumod"
@@ -14,5 +18,5 @@
   },
   "blurb": "Given a letter, print a diamond starting with 'A' with the supplied letter at the widest point.",
   "source": "Seb Rose",
-  "source_url": "http://claysnow.co.uk/recycling-tests-in-tdd/"
+  "source_url": "https://web.archive.org/web/20220807163751/http://claysnow.co.uk/recycling-tests-in-tdd/"
 }

exercises/practice/hello-world/.meta/config.json

@@ -17,7 +17,7 @@
       ".meta/solutions/HelloWorld.rakumod"
     ]
   },
-  "blurb": "The classical introductory exercise. Just say \"Hello, World!\".",
+  "blurb": "Exercism's classic introductory exercise. Just say \"Hello, World!\".",
   "source": "This is an exercise to introduce users to using Exercism",
   "source_url": "https://en.wikipedia.org/wiki/%22Hello,_world!%22_program"
 }

exercises/practice/isogram/.docs/instructions.md

@@ -11,4 +11,4 @@ Examples of isograms:
 - downstream
 - six-year-old
 
-The word *isograms*, however, is not an isogram, because the s repeats.
+The word _isograms_, however, is not an isogram, because the s repeats.

exercises/practice/meetup/.meta/config.json

@@ -15,5 +15,5 @@
   },
   "blurb": "Calculate the date of meetups.",
   "source": "Jeremy Hinegardner mentioned a Boulder meetup that happens on the Wednesteenth of every month",
-  "source_url": "https://twitter.com/copiousfreetime"
+  "source_url": "http://www.copiousfreetime.org/"
 }

exercises/practice/perfect-numbers/.docs/instructions.md

@@ -2,22 +2,38 @@
 
 Determine if a number is perfect, abundant, or deficient based on Nicomachus' (60 - 120 CE) classification scheme for positive integers.
 
-The Greek mathematician [Nicomachus][nicomachus] devised a classification scheme for positive integers, identifying each as belonging uniquely to the categories of **perfect**, **abundant**, or **deficient** based on their [aliquot sum][aliquot-sum].
-The aliquot sum is defined as the sum of the factors of a number not including the number itself.
-For example, the aliquot sum of 15 is: (1 + 3 + 5) = 9
-
-- **Perfect**: aliquot sum = number
-  - 6 is a perfect number because (1 + 2 + 3) = 6
-  - 28 is a perfect number because (1 + 2 + 4 + 7 + 14) = 28
-- **Abundant**: aliquot sum > number
-  - 12 is an abundant number because (1 + 2 + 3 + 4 + 6) = 16
-  - 24 is an abundant number because (1 + 2 + 3 + 4 + 6 + 8 + 12) = 36
-- **Deficient**: aliquot sum < number
-  - 8 is a deficient number because (1 + 2 + 4) = 7
-  - Prime numbers are deficient
-
-Implement a way to determine whether a given number is **perfect**.
-Depending on your language track, you may also need to implement a way to determine whether a given number is **abundant** or **deficient**.
+The Greek mathematician [Nicomachus][nicomachus] devised a classification scheme for positive integers, identifying each as belonging uniquely to the categories of [perfect](#perfect), [abundant](#abundant), or [deficient](#deficient) based on their [aliquot sum][aliquot-sum].
+The _aliquot sum_ is defined as the sum of the factors of a number not including the number itself.
+For example, the aliquot sum of `15` is `1 + 3 + 5 = 9`.
+
+## Perfect
+
+A number is perfect when it equals its aliquot sum.
+For example:
+
+- `6` is a perfect number because `1 + 2 + 3 = 6`
+- `28` is a perfect number because `1 + 2 + 4 + 7 + 14 = 28`
+
+## Abundant
+
+A number is abundant when it is less than its aliquot sum.
+For example:
+
+- `12` is an abundant number because `1 + 2 + 3 + 4 + 6 = 16`
+- `24` is an abundant number because `1 + 2 + 3 + 4 + 6 + 8 + 12 = 36`
+
+## Deficient
+
+A number is deficient when it is greater than its aliquot sum.
+For example:
+
+- `8` is a deficient number because `1 + 2 + 4 = 7`
+- Prime numbers are deficient
+
+## Task
+
+Implement a way to determine whether a given number is [perfect](#perfect).
+Depending on your language track, you may also need to implement a way to determine whether a given number is [abundant](#abundant) or [deficient](#deficient).
 
 [nicomachus]: https://en.wikipedia.org/wiki/Nicomachus
 [aliquot-sum]: https://en.wikipedia.org/wiki/Aliquot_sum

exercises/practice/phone-number/.docs/instructions.md

@@ -5,18 +5,20 @@ Clean up user-entered phone numbers so that they can be sent SMS messages.
 The **North American Numbering Plan (NANP)** is a telephone numbering system used by many countries in North America like the United States, Canada or Bermuda.
 All NANP-countries share the same international country code: `1`.
 
-NANP numbers are ten-digit numbers consisting of a three-digit Numbering Plan Area code, commonly known as *area code*, followed by a seven-digit local number.
-The first three digits of the local number represent the *exchange code*, followed by the unique four-digit number which is the *subscriber number*.
+NANP numbers are ten-digit numbers consisting of a three-digit Numbering Plan Area code, commonly known as _area code_, followed by a seven-digit local number.
+The first three digits of the local number represent the _exchange code_, followed by the unique four-digit number which is the _subscriber number_.
 
 The format is usually represented as
 
 ```text
-(NXX)-NXX-XXXX
+NXX NXX-XXXX
 ```
 
 where `N` is any digit from 2 through 9 and `X` is any digit from 0 through 9.
 
-Your task is to clean up differently formatted telephone numbers by removing punctuation and the country code (1) if present.
+Sometimes they also have the country code (represented as `1` or `+1`) prefixed.
+
+Your task is to clean up differently formatted telephone numbers by removing punctuation and the country code if present.
 
 For example, the inputs
 

exercises/practice/pythagorean-triplet/.meta/config.json

@@ -13,7 +13,7 @@
       ".meta/solutions/PythagoreanTriplet.rakumod"
     ]
   },
-  "blurb": "There exists exactly one Pythagorean triplet for which a + b + c = 1000. Find the product a * b * c.",
+  "blurb": "There exists exactly one Pythagorean triplet for which a + b + c = 1000. Find the triplet.",
   "source": "Problem 9 at Project Euler",
   "source_url": "https://projecteuler.net/problem=9"
 }

exercises/practice/queen-attack/.docs/instructions.md

@@ -8,18 +8,14 @@ A chessboard can be represented by an 8 by 8 array.
 
 So if you are told the white queen is at `c5` (zero-indexed at column 2, row 3) and the black queen at `f2` (zero-indexed at column 5, row 6), then you know that the set-up is like so:
 
-```text
-  a b c d e f g h
-8 _ _ _ _ _ _ _ _ 8
-7 _ _ _ _ _ _ _ _ 7
-6 _ _ _ _ _ _ _ _ 6
-5 _ _ W _ _ _ _ _ 5
-4 _ _ _ _ _ _ _ _ 4
-3 _ _ _ _ _ _ _ _ 3
-2 _ _ _ _ _ B _ _ 2
-1 _ _ _ _ _ _ _ _ 1
-  a b c d e f g h
-```
+![A chess board with two queens. Arrows emanating from the queen at c5 indicate possible directions of capture along file, rank and diagonal.](https://assets.exercism.org/images/exercises/queen-attack/queen-capture.svg)
 
 You are also able to answer whether the queens can attack each other.
 In this case, that answer would be yes, they can, because both pieces share a diagonal.
+
+## Credit
+
+The chessboard image was made by [habere-et-dispertire][habere-et-dispertire] using LaTeX and the [chessboard package][chessboard-package] by Ulrike Fischer.
+
+[habere-et-dispertire]: https://exercism.org/profiles/habere-et-dispertire
+[chessboard-package]: https://github.com/u-fischer/chessboard

exercises/practice/roman-numerals/.docs/instructions.md

@@ -9,8 +9,7 @@ One thing they never discovered though was the number zero.
 This made writing and dating extensive histories of their exploits slightly more challenging, but the system of numbers they came up with is still in use today.
 For example the BBC uses Roman numerals to date their programs.
 
-The Romans wrote numbers using letters - I, V, X, L, C, D, M.
-(notice these letters have lots of straight lines and are hence easy to hack into stone tablets).
+The Romans wrote numbers using letters - I, V, X, L, C, D, M; notice these letters have lots of straight lines and are hence easy to hack into stone tablets.
 
 ```text
  1  => I
@@ -19,22 +18,29 @@ The Romans wrote numbers using letters - I, V, X, L, C, D, M.
 ```
 
 The maximum number supported by this notation is 3,999.
-(The Romans themselves didn't tend to go any higher)
 
-Wikipedia says: Modern Roman numerals ... are written by expressing each digit separately starting with the left most digit and skipping any digit with a value of zero.
+Wikipedia says: Modern Roman numerals [...] are written by expressing each digit separately starting with the left most digit and skipping any digit with a value of zero.
 
 To see this in practice, consider the example of 1990.
 
 In Roman numerals 1990 is MCMXC:
 
-1000=M
-900=CM
-90=XC
+```text
+ 1000 => M
+  900 => CM
++  90 => XC
+----- => -----
+ 1990 => MCMXC
+```
 
 2008 is written as MMVIII:
 
-2000=MM
-8=VIII
+```text
+ 2000 => MM
++   8 => VIII
+----- => ------
+ 2008 => MMVIII
+```
 
 Learn more about [Roman numerals on Wikipedia][roman-numerals].
 

exercises/practice/rotational-cipher/.docs/instructions.md

@@ -22,8 +22,8 @@ Ciphertext is written out in the same formatting as the input including spaces a
 
 ## Examples
 
-- ROT5  `omg` gives `trl`
-- ROT0  `c` gives `c`
+- ROT5 `omg` gives `trl`
+- ROT0 `c` gives `c`
 - ROT26 `Cool` gives `Cool`
 - ROT13 `The quick brown fox jumps over the lazy dog.` gives `Gur dhvpx oebja sbk whzcf bire gur ynml qbt.`
 - ROT13 `Gur dhvpx oebja sbk whzcf bire gur ynml qbt.` gives `The quick brown fox jumps over the lazy dog.`

exercises/practice/secret-handshake/.meta/config.json

@@ -15,5 +15,5 @@
   },
   "blurb": "Given a decimal number, convert it to the appropriate sequence of events for a secret handshake.",
   "source": "Bert, in Mary Poppins",
-  "source_url": "https://www.imdb.com/title/tt0058331/quotes/qt0437047"
+  "source_url": "https://www.imdb.com/title/tt0058331/quotes/?item=qt0437047"
 }

exercises/practice/series/.docs/instructions.md

@@ -15,5 +15,5 @@ And the following 4-digit series:
 
 And if you ask for a 6-digit series from a 5-digit string, you deserve whatever you get.
 
-Note that these series are only required to occupy *adjacent positions* in the input;
-the digits need not be *numerically consecutive*.
+Note that these series are only required to occupy _adjacent positions_ in the input;
+the digits need not be _numerically consecutive_.