🤖 Auto-sync docs, metadata, and filepaths (#2433)

Author: github-actions[bot]

exercises/practice/dot-dsl/.docs/instructions.md

@@ -22,7 +22,7 @@ Write a Domain Specific Language similar to the Graphviz dot language.
 Our DSL is similar to the Graphviz dot language in that our DSL will be used to create graph data structures.
 However, unlike the DOT Language, our DSL will be an internal DSL for use only in our language.
 
-More information about the difference between internal and external DSLs can be found [here][fowler-dsl].
+[Learn more about the difference between internal and external DSLs][fowler-dsl].
 
 [dsl]: https://en.wikipedia.org/wiki/Domain-specific_language
 [dot-language]: https://en.wikipedia.org/wiki/DOT_(graph_description_language)

exercises/practice/flower-field/.meta/config.json

@@ -18,6 +18,9 @@
     ],
     "example": [
       ".meta/Example.cs"
+    ],
+    "invalidator": [
+      "FlowerField.csproj"
     ]
   },
   "blurb": "Mark all the flowers in a garden."

exercises/practice/intergalactic-transmission/.docs/instructions.md

@@ -7,7 +7,7 @@ Your job is to help implement
 
 A parity bit is simple way of detecting transmission errors.
 The transmitters and receivers can only transmit and receive _exactly_ eight bits at a time (including the parity bit).
-The parity bit is set so that there is an _even_ number 1s in each transmission and is always the first bit from the right.
+The parity bit is set so that there is an _even_ number of 1 bits in each transmission, and the parity bit is always the first bit from the right.
 So if the receiver receives `11000001`, `01110101` or `01000000` (i.e. a transmission with an odd number of 1 bits), it knows there is an error.
 
 However, messages are rarely this short, and need to be transmitted in a sequence when they are longer.
@@ -40,7 +40,7 @@ Their parity bits are set to 1 so that they have an even number of 1 bits in the
 They are transmitted as `01110001` and `00011011` (or `71` and `1B` in hex).
 
 The last transmission (`1110`) has only four bits of data.
-Since exactly eight bits are transmitted at a time and the parity bit is the right most bit, three 0 bits and then the parity bit are added to make up eight bits.
+Since exactly eight bits are transmitted at a time and the parity bit is the rightmost bit, three 0 bits and then the parity bit are added to make up eight bits.
 It now looks like this (where `_` is the parity bit):
 
 ```text

exercises/practice/luhn/.docs/instructions.md

@@ -41,7 +41,7 @@ If the sum is evenly divisible by 10, the original number is valid.
 
 ### Invalid Canadian SIN
 
-The number to be checked is `066 123 468`.
+The number to be checked is `066 123 478`.
 
 We start at the end of the number and double every second digit, beginning with the second digit from the right and moving left.
 

exercises/practice/protein-translation/.docs/instructions.md

@@ -1,36 +1,17 @@
 # Instructions
 
-Translate RNA sequences into proteins.
+Your job is to translate RNA sequences into proteins.
 
-RNA can be broken into three-nucleotide sequences called codons, and then translated to a protein like so:
+RNA strands are made up of three-nucleotide sequences called **codons**.
+Each codon translates to an **amino acid**.
+When joined together, those amino acids make a protein.
 
-RNA: `"AUGUUUUCU"` => translates to
-
-Codons: `"AUG", "UUU", "UCU"`
-=> which become a protein with the following sequence =>
-
-Protein: `"Methionine", "Phenylalanine", "Serine"`
-
-There are 64 codons which in turn correspond to 20 amino acids; however, all of the codon sequences and resulting amino acids are not important in this exercise.
-If it works for one codon, the program should work for all of them.
-However, feel free to expand the list in the test suite to include them all.
-
-There are also three terminating codons (also known as 'STOP' codons); if any of these codons are encountered (by the ribosome), all translation ends and the protein is terminated.
-
-All subsequent codons after are ignored, like this:
-
-RNA: `"AUGUUUUCUUAAAUG"` =>
-
-Codons: `"AUG", "UUU", "UCU", "UAA", "AUG"` =>
-
-Protein: `"Methionine", "Phenylalanine", "Serine"`
-
-Note the stop codon `"UAA"` terminates the translation and the final methionine is not translated into the protein sequence.
-
-Below are the codons and resulting amino acids needed for the exercise.
+In the real world, there are 64 codons, which in turn correspond to 20 amino acids.
+However, for this exercise, you’ll only use a few of the possible 64.
+They are listed below:
 
 | Codon              | Amino Acid    |
-| :----------------- | :------------ |
+| ------------------ | ------------- |
 | AUG                | Methionine    |
 | UUU, UUC           | Phenylalanine |
 | UUA, UUG           | Leucine       |
@@ -40,6 +21,18 @@ Below are the codons and resulting amino acids needed for the exercise.
 | UGG                | Tryptophan    |
 | UAA, UAG, UGA      | STOP          |
 
+For example, the RNA string “AUGUUUUCU” has three codons: “AUG”, “UUU” and “UCU”.
+These map to Methionine, Phenylalanine, and Serine.
+
+## “STOP” Codons
+
+You’ll note from the table above that there are three **“STOP” codons**.
+If you encounter any of these codons, ignore the rest of the sequence — the protein is complete.
+
+For example, “AUGUUUUCUUAAAUG” contains a STOP codon (“UAA”).
+Once we reach that point, we stop processing.
+We therefore only consider the part before it (i.e. “AUGUUUUCU”), not any further codons after it (i.e. “AUG”).
+
 Learn more about [protein translation on Wikipedia][protein-translation].
 
 [protein-translation]: https://en.wikipedia.org/wiki/Translation_(biology)

exercises/practice/relative-distance/.docs/instructions.md

@@ -1,6 +1,7 @@
 # Instructions
 
 Your task is to determine the degree of separation between two individuals in a family tree.
+This is similar to the pop culture idea that every Hollywood actor is [within six degrees of Kevin Bacon][six-bacons].
 
 - You will be given an input, with all parent names and their children.
 - Each name is unique, a child _can_ have one or two parents.
@@ -13,22 +14,21 @@ Your task is to determine the degree of separation between two individuals in a
 Given the following family tree:
 
 ```text
-      ┌──────────┐            ┌──────────┐ ┌───────────┐
-      │  Helena  │            │  Erdős   │ │  Shusaku  │
-      └───┬───┬──┘            └─────┬────┘ └──────┬────┘
-      ┌───┘   └───────┐             └──────┬──────┘
-      ▼               ▼                    ▼
-┌──────────┐     ┌────────┐          ┌──────────┐
-│   Isla   │     │  Tariq │          │   Kevin  │
-└────┬─────┘     └────┬───┘          └──────────┘
-     ▼                ▼
-┌─────────┐      ┌────────┐
+      ┌──────────┐            ┌──────────┐     ┌───────────┐
+      │  Helena  │            │  Erdős   ├─────┤  Shusaku  │
+      └───┬───┬──┘            └─────┬────┘     └────┬──────┘
+      ┌───┘   └───────┐             └───────┬───────┘
+┌─────┴────┐     ┌────┴───┐           ┌─────┴────┐
+│   Isla   ├─────┤ Tariq  │           │   Kevin  │
+└────┬─────┘     └────┬───┘           └──────────┘
+     │                │
+┌────┴────┐      ┌────┴───┐
 │   Uma   │      │ Morphy │
 └─────────┘      └────────┘
 ```
 
-The degree of separation between Tariq and Uma is 3 (Tariq → Helena → Isla → Uma).
-There's no known relationship between Isla and [Kevin][six-bacons], as there is no connection in the given data.
+The degree of separation between Tariq and Uma is 2 (Tariq → Isla → Uma).
+There's no known relationship between Isla and Kevin, as there is no connection in the given data.
 The degree of separation between Uma and Isla is 1.
 
 ~~~~exercism/note

exercises/practice/relative-distance/.meta/config.json

@@ -11,6 +11,9 @@
     ],
     "example": [
       ".meta/Example.cs"
+    ],
+    "invalidator": [
+      "RelativeDistance.csproj"
     ]
   },
   "blurb": "Given a family tree, calculate the degree of separation.",

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

@@ -1,66 +1,40 @@
 # Instructions
 
-Implement a simple shift cipher like Caesar and a more secure substitution cipher.
+Create an implementation of the [Vigenère cipher][wiki].
+The Vigenère cipher is a simple substitution cipher.
 
-## Step 1
+## Cipher terminology
 
-"If he had anything confidential to say, he wrote it in cipher, that is, by so changing the order of the letters of the alphabet, that not a word could be made out.
-If anyone wishes to decipher these, and get at their meaning, he must substitute the fourth letter of the alphabet, namely D, for A, and so with the others."
-—Suetonius, Life of Julius Caesar
+A cipher is an algorithm used to encrypt, or encode, a string.
+The unencrypted string is called the _plaintext_ and the encrypted string is called the _ciphertext_.
+Converting plaintext to ciphertext is called _encoding_ while the reverse is called _decoding_.
 
-Ciphers are very straight-forward algorithms that allow us to render text less readable while still allowing easy deciphering.
-They are vulnerable to many forms of cryptanalysis, but Caesar was lucky that his enemies were not cryptanalysts.
+In a _substitution cipher_, each plaintext letter is replaced with a ciphertext letter which is computed with the help of a _key_.
+(Note, it is possible for replacement letter to be the same as the original letter.)
 
-The Caesar cipher was used for some messages from Julius Caesar that were sent afield.
-Now Caesar knew that the cipher wasn't very good, but he had one ally in that respect: almost nobody could read well.
-So even being a couple letters off was sufficient so that people couldn't recognize the few words that they did know.
+## Encoding details
 
-Your task is to create a simple shift cipher like the Caesar cipher.
-This image is a great example of the Caesar cipher:
+In this cipher, the key is a series of lowercase letters, such as `"abcd"`.
+Each letter of the plaintext is _shifted_ or _rotated_ by a distance based on a corresponding letter in the key.
+An `"a"` in the key means a shift of 0 (that is, no shift).
+A `"b"` in the key means a shift of 1.
+A `"c"` in the key means a shift of 2, and so on.
 
-![Caesar cipher][img-caesar-cipher]
+The first letter of the plaintext uses the first letter of the key, the second letter of the plaintext uses the second letter of the key and so on.
+If you run out of letters in the key before you run out of letters in the plaintext, start over from the start of the key again.
 
-For example:
+If the key only contains one letter, such as `"dddddd"`, then all letters of the plaintext are shifted by the same amount (three in this example), which would make this the same as a rotational cipher or shift cipher (sometimes called a Caesar cipher).
+For example, the plaintext `"iamapandabear"` would become `"ldpdsdqgdehdu"`.
 
-Giving "iamapandabear" as input to the encode function returns the cipher "ldpdsdqgdehdu".
-Obscure enough to keep our message secret in transit.
+If the key only contains the letter `"a"` (one or more times), the shift distance is zero and the ciphertext is the same as the plaintext.
 
-When "ldpdsdqgdehdu" is put into the decode function it would return the original "iamapandabear" letting your friend read your original message.
+Usually the key is more complicated than that, though!
+If the key is `"abcd"` then letters of the plaintext would be shifted by a distance of 0, 1, 2, and 3.
+If the plaintext is `"hello"`, we need 5 shifts so the key would wrap around, giving shift distances of 0, 1, 2, 3, and 0.
+Applying those shifts to the letters of `"hello"` we get `"hfnoo"`.
 
-## Step 2
+## Random keys
 
-Shift ciphers quickly cease to be useful when the opposition commander figures them out.
-So instead, let's try using a substitution cipher.
-Try amending the code to allow us to specify a key and use that for the shift distance.
+If no key is provided, generate a key which consists of at least 100 random lowercase letters from the Latin alphabet.
 
-Here's an example:
-
-Given the key "aaaaaaaaaaaaaaaaaa", encoding the string "iamapandabear"
-would return the original "iamapandabear".
-
-Given the key "ddddddddddddddddd", encoding our string "iamapandabear"
-would return the obscured "ldpdsdqgdehdu"
-
-In the example above, we've set a = 0 for the key value.
-So when the plaintext is added to the key, we end up with the same message coming out.
-So "aaaa" is not an ideal key.
-But if we set the key to "dddd", we would get the same thing as the Caesar cipher.
-
-## Step 3
-
-The weakest link in any cipher is the human being.
-Let's make your substitution cipher a little more fault tolerant by providing a source of randomness and ensuring that the key contains only lowercase letters.
-
-If someone doesn't submit a key at all, generate a truly random key of at least 100 lowercase characters in length.
-
-## Extensions
-
-Shift ciphers work by making the text slightly odd, but are vulnerable to frequency analysis.
-Substitution ciphers help that, but are still very vulnerable when the key is short or if spaces are preserved.
-Later on you'll see one solution to this problem in the exercise "crypto-square".
-
-If you want to go farther in this field, the questions begin to be about how we can exchange keys in a secure way.
-Take a look at [Diffie-Hellman on Wikipedia][dh] for one of the first implementations of this scheme.
-
-[img-caesar-cipher]: https://upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Caesar_cipher_left_shift_of_3.svg/320px-Caesar_cipher_left_shift_of_3.svg.png
-[dh]: https://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange
+[wiki]: https://en.wikipedia.org/wiki/Vigen%C3%A8re_cipher

exercises/practice/simple-cipher/.meta/config.json

@@ -25,7 +25,7 @@
       "SimpleCipher.csproj"
     ]
   },
-  "blurb": "Implement a simple shift cipher like Caesar and a more secure substitution cipher.",
+  "blurb": "Implement the Vigenère cipher, a simple substitution cipher.",
   "source": "Substitution Cipher at Wikipedia",
   "source_url": "https://en.wikipedia.org/wiki/Substitution_cipher"
 }