Sync docs and metadata

exercises/practice/accumulate/.docs/instructions.md

@@ -1,9 +1,6 @@
 # Instructions
 
-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.
+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.
 
 Given the collection of numbers:
 
@@ -21,6 +18,5 @@ Check out the test suite to see the expected function signature.
 
 ## Restrictions
 
-Keep your hands off that collect/map/fmap/whatchamacallit functionality
-provided by your standard library!
+Keep your hands off that collect/map/fmap/whatchamacallit functionality provided by your standard library!
 Solve this one yourself using other basic tools instead.

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

@@ -26,5 +26,5 @@
   },
   "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

@@ -4,5 +4,14 @@ Convert a phrase to its acronym.
 
 Techies love their TLA (Three Letter Acronyms)!
 
-Help generate some jargon by writing a program that converts a long name
-like Portable Network Graphics to its acronym (PNG).
+Help generate some jargon by writing a program that converts a long name like Portable Network Graphics to its acronym (PNG).
+
+Punctuation is handled as follows: hyphens are word separators (like whitespace); all other punctuation can be removed from the input.
+
+For example:
+
+| Input                     | Output |
+| ------------------------- | ------ |
+| As Soon As Possible       | ASAP   |
+| Liquid-crystal display    | LCD    |
+| Thank George It's Friday! | TGIF   |

exercises/practice/acronym/.meta/config.json

@@ -18,7 +18,7 @@
       ".meta/src/example.clj"
     ]
   },
-  "blurb": "Convert a long phrase to its acronym",
+  "blurb": "Convert a long phrase to its acronym.",
   "source": "Julien Vanier",
   "source_url": "https://github.com/monkbroc"
 }

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

@@ -1,27 +1,37 @@
 # Instructions
 
-Convert a sequence of digits in one base, representing a number, into a sequence of digits in another base, representing the same number.
+Convert a number, represented as a sequence of digits in one base, to any other base.
 
-~~~~exercism/note
-Try to implement the conversion yourself.
-Do not use something else to perform the conversion for you.
-~~~~
+Implement general base conversion.
+Given a number in base **a**, represented as a sequence of digits, convert it to base **b**.
 
+## Note
+
+- Try to implement the conversion yourself.
+  Do not use something else to perform the conversion for you.
+
+## About [Positional Notation][positional-notation]
 ## About [Positional Notation][positional-notation]
 
+In positional notation, a number in base **b** can be understood as a linear combination of powers of **b**.
 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 × 10¹) + (2 × 10⁰)`
+`(4 * 10^1) + (2 * 10^0)`
 
+The number 101010, _in base 2_, means:
 The number 101010, _in base 2_, means:
 
-`(1 × 2⁵) + (0 × 2⁴) + (1 × 2³) + (0 × 2²) + (1 × 2¹) + (0 × 2⁰)`
+`(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 × 3³) + (1 × 3²) + (2 × 3¹) + (0 × 3⁰)`
+`(1 * 3^3) + (1 * 3^2) + (2 * 3^1) + (0 * 3^0)`
+
+_Yes. Those three numbers above are exactly the same. Congratulations!_
 
 _Yes. Those three numbers above are exactly the same. Congratulations!_
 

exercises/practice/anagram/.docs/instructions.md

@@ -1,9 +1,9 @@
 # Instructions
 
-Your task is to, given a target word and a set of candidate words, to find the subset of the candidates that are anagrams of the target.
-
 An anagram is a rearrangement of letters to form a new word: for example `"owns"` is an anagram of `"snow"`.
-A word is _not_ its own anagram: for example, `"stop"` is not an anagram of `"stop"`.
+A word is not its own anagram: for example, `"stop"` is not an anagram of `"stop"`.
+
+Given a target word and a set of candidate words, this exercise requests the anagram set: the subset of the candidates that are anagrams of the target.
 
 The target and candidates are words of one or more ASCII alphabetic characters (`A`-`Z` and `a`-`z`).
 Lowercase and uppercase characters are equivalent: for example, `"PoTS"` is an anagram of `"sTOp"`, but `StoP` is not an anagram of `sTOp`.

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/atbash-cipher/.docs/instructions.md

@@ -2,10 +2,8 @@
 
 Create an implementation of the atbash cipher, an ancient encryption system created in the Middle East.
 
-The Atbash cipher is a simple substitution cipher that relies on
-transposing all the letters in the alphabet such that the resulting
-alphabet is backwards. The first letter is replaced with the last
-letter, the second with the second-last, and so on.
+The Atbash cipher is a simple substitution cipher that relies on transposing all the letters in the alphabet such that the resulting alphabet is backwards.
+The first letter is replaced with the last letter, the second with the second-last, and so on.
 
 An Atbash cipher for the Latin alphabet would be as follows:
 
@@ -14,16 +12,16 @@ Plain:  abcdefghijklmnopqrstuvwxyz
 Cipher: zyxwvutsrqponmlkjihgfedcba
 ```
 
-It is a very weak cipher because it only has one possible key, and it is
-a simple monoalphabetic substitution cipher. However, this may not have
-been an issue in the cipher's time.
+It is a very weak cipher because it only has one possible key, and it is a simple mono-alphabetic substitution cipher.
+However, this may not have been an issue in the cipher's time.
 
-Ciphertext is written out in groups of fixed length, the traditional group size
-being 5 letters, and punctuation is excluded. This is to make it harder to guess
-things based on word boundaries.
+Ciphertext is written out in groups of fixed length, the traditional group size being 5 letters, leaving numbers unchanged, and punctuation is excluded.
+This is to make it harder to guess things based on word boundaries.
+All text will be encoded as lowercase letters.
 
 ## Examples
 
 - Encoding `test` gives `gvhg`
+- Encoding `x123 yes` gives `c123b vh`
 - Decoding `gvhg` gives `test`
 - Decoding `gsvjf rxpyi ldmul cqfnk hlevi gsvoz abwlt` gives `thequickbrownfoxjumpsoverthelazydog`

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

@@ -25,5 +25,5 @@
   },
   "blurb": "Create an implementation of the atbash cipher, an ancient encryption system created in the Middle East.",
   "source": "Wikipedia",
-  "source_url": "http://en.wikipedia.org/wiki/Atbash"
+  "source_url": "https://en.wikipedia.org/wiki/Atbash"
 }

exercises/practice/bank-account/.docs/instructions.md

@@ -1,10 +1,12 @@
 # Instructions
 
-Your task is to implement bank accounts supporting opening/closing, withdrawals, and deposits of money.
+Simulate a bank account supporting opening/closing, withdrawals, and deposits of money.
+Watch out for concurrent transactions!
 
-As bank accounts can be accessed in many different ways (internet, mobile phones, automatic charges), your bank software must allow accounts to be safely accessed from multiple threads/processes (terminology depends on your programming language) in parallel.
-For example, there may be many deposits and withdrawals occurring in parallel; you need to ensure there is no [race conditions][wikipedia] between when you read the account balance and set the new balance.
+A bank account can be accessed in multiple ways.
+Clients can make deposits and withdrawals using the internet, mobile phones, etc.
+Shops can charge against the account.
 
-It should be possible to close an account; operations against a closed account must fail.
+Create an account that can be accessed from multiple threads/processes (terminology depends on your programming language).
 
-[wikipedia]: https://en.wikipedia.org/wiki/Race_condition#In_software
+It should be possible to close an account; operations against a closed account must fail.

exercises/practice/beer-song/.docs/instructions.md

@@ -305,17 +305,3 @@ Take it down and pass it around, no more bottles of beer on the wall.
 No more bottles of beer on the wall, no more bottles of beer.
 Go to the store and buy some more, 99 bottles of beer on the wall.
 ```
-
-## For bonus points
-
-Did you get the tests passing and the code clean? If you want to, these
-are some additional things you could try:
-
-* Remove as much duplication as you possibly can.
-* Optimize for readability, even if it means introducing duplication.
-* If you've removed all the duplication, do you have a lot of
-  conditionals? Try replacing the conditionals with polymorphism, if it
-  applies in this language. How readable is it?
-
-Then please share your thoughts in a comment on the submission. Did this
-experiment make the code better? Worse? Did you learn anything from it?

exercises/practice/beer-song/.meta/config.json

@@ -30,5 +30,5 @@
   },
   "blurb": "Produce the lyrics to that beloved classic, that field-trip favorite: 99 Bottles of Beer on the Wall.",
   "source": "Learn to Program by Chris Pine",
-  "source_url": "http://pine.fm/LearnToProgram/?Chapter=06"
+  "source_url": "https://pine.fm/LearnToProgram/?Chapter=06"
 }

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

@@ -2,29 +2,22 @@
 
 Insert and search for numbers in a binary tree.
 
-When we need to represent sorted data, an array does not make a good
-data structure.
-
-Say we have the array `[1, 3, 4, 5]`, and we add 2 to it so it becomes
-`[1, 3, 4, 5, 2]` now we must sort the entire array again! We can
-improve on this by realizing that we only need to make space for the new
-item `[1, nil, 3, 4, 5]`, and then adding the item in the space we
-added. But this still requires us to shift many elements down by one.
-
-Binary Search Trees, however, can operate on sorted data much more
-efficiently.
-
-A binary search tree consists of a series of connected nodes. Each node
-contains a piece of data (e.g. the number 3), a variable named `left`,
-and a variable named `right`. The `left` and `right` variables point at
-`nil`, or other nodes. Since these other nodes in turn have other nodes
-beneath them, we say that the left and right variables are pointing at
-subtrees. All data in the left subtree is less than or equal to the
-current node's data, and all data in the right subtree is greater than
-the current node's data.
-
-For example, if we had a node containing the data 4, and we added the
-data 2, our tree would look like this:
+When we need to represent sorted data, an array does not make a good data structure.
+
+Say we have the array `[1, 3, 4, 5]`, and we add 2 to it so it becomes `[1, 3, 4, 5, 2]`.
+Now we must sort the entire array again!
+We can improve on this by realizing that we only need to make space for the new item `[1, nil, 3, 4, 5]`, and then adding the item in the space we added.
+But this still requires us to shift many elements down by one.
+
+Binary Search Trees, however, can operate on sorted data much more efficiently.
+
+A binary search tree consists of a series of connected nodes.
+Each node contains a piece of data (e.g. the number 3), a variable named `left`, and a variable named `right`.
+The `left` and `right` variables point at `nil`, or other nodes.
+Since these other nodes in turn have other nodes beneath them, we say that the left and right variables are pointing at subtrees.
+All data in the left subtree is less than or equal to the current node's data, and all data in the right subtree is greater than the current node's data.
+
+For example, if we had a node containing the data 4, and we added the data 2, our tree would look like this:
 
       4
      /

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

@@ -24,6 +24,5 @@
     ]
   },
   "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/.docs/instructions.md

@@ -2,9 +2,9 @@
 
 Convert a binary number, represented as a string (e.g. '101010'), to its decimal equivalent using first principles.
 
-Implement binary to decimal conversion. Given a binary input
-string, your program should produce a decimal output. The
-program should handle invalid inputs.
+Implement binary to decimal conversion.
+Given a binary input string, your program should produce a decimal output.
+The program should handle invalid inputs.
 
 ## Note
 
@@ -15,13 +15,12 @@ program should handle invalid inputs.
 
 Decimal is a base-10 system.
 
-A number 23 in base 10 notation can be understood
-as a linear combination of powers of 10:
+A number 23 in base 10 notation can be understood as a linear combination of powers of 10:
 
 - The rightmost digit gets multiplied by 10^0 = 1
 - The next number gets multiplied by 10^1 = 10
 - ...
-- The *n*th number gets multiplied by 10^*(n-1)*.
+- The nth number gets multiplied by 10^_(n-1)_.
 - All these values are summed.
 
 So: `23 => 2*10^1 + 3*10^0 => 2*10 + 3*1 = 23 base 10`

exercises/practice/binary/.meta/config.json

@@ -24,7 +24,7 @@
       ".meta/src/example.clj"
     ]
   },
-  "blurb": "Convert a binary number, represented as a string (e.g. '101010'), to its decimal equivalent using first principles",
+  "blurb": "Convert a binary number, represented as a string (e.g. '101010'), to its decimal equivalent using first principles.",
   "source": "All of Computer Science",
-  "source_url": "http://www.wolframalpha.com/input/?i=binary&a=*C.binary-_*MathWorld-"
+  "source_url": "https://www.wolframalpha.com/examples/mathematics/numbers/base-conversions"
 }

exercises/practice/bob/.meta/config.json

@@ -34,5 +34,5 @@
   },
   "blurb": "Bob is a lackadaisical teenager. In conversation, his responses are very limited.",
   "source": "Inspired by the 'Deaf Grandma' exercise in Chris Pine's Learn to Program tutorial.",
-  "source_url": "http://pine.fm/LearnToProgram/?Chapter=06"
+  "source_url": "https://pine.fm/LearnToProgram/?Chapter=06"
 }

exercises/practice/change/.docs/instructions.md

@@ -1,14 +1,11 @@
 # Instructions
 
-Correctly determine the fewest number of coins to be given to a customer such
-that the sum of the coins' value would equal the correct amount of change.
+Correctly determine the fewest number of coins to be given to a customer such that the sum of the coins' value would equal the correct amount of change.
 
 ## For example
 
-- An input of 15 with [1, 5, 10, 25, 100] should return one nickel (5)
-  and one dime (10) or [5, 10]
-- An input of 40 with [1, 5, 10, 25, 100] should return one nickel (5)
-  and one dime (10) and one quarter (25) or [5, 10, 25]
+- An input of 15 with [1, 5, 10, 25, 100] should return one nickel (5) and one dime (10) or [5, 10]
+- An input of 40 with [1, 5, 10, 25, 100] should return one nickel (5) and one dime (10) and one quarter (25) or [5, 10, 25]
 
 ## Edge cases
 

exercises/practice/change/.meta/config.json

@@ -19,7 +19,7 @@
       ".meta/src/example.clj"
     ]
   },
-  "blurb": "Correctly determine change to be given using the least number of coins",
+  "blurb": "Correctly determine change to be given using the least number of coins.",
   "source": "Software Craftsmanship - Coin Change Kata",
   "source_url": "https://web.archive.org/web/20130115115225/http://craftsmanship.sv.cmu.edu:80/exercises/coin-change-kata"
 }

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

@@ -18,6 +18,5 @@
     ]
   },
   "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/collatz-conjecture/.docs/instructions.md

@@ -2,10 +2,11 @@
 
 The Collatz Conjecture or 3x+1 problem can be summarized as follows:
 
-Take any positive integer n. If n is even, divide n by 2 to get n / 2. If n is
-odd, multiply n by 3 and add 1 to get 3n + 1. Repeat the process indefinitely.
-The conjecture states that no matter which number you start with, you will
-always reach 1 eventually.
+Take any positive integer n.
+If n is even, divide n by 2 to get n / 2.
+If n is odd, multiply n by 3 and add 1 to get 3n + 1.
+Repeat the process indefinitely.
+The conjecture states that no matter which number you start with, you will always reach 1 eventually.
 
 Given a number n, return the number of steps required to reach 1.
 
@@ -24,4 +25,5 @@ Starting with n = 12, the steps would be as follows:
 8. 2
 9. 1
 
-Resulting in 9 steps. So for input n = 12, the return value would be 9.
+Resulting in 9 steps.
+So for input n = 12, the return value would be 9.

exercises/practice/collatz-conjecture/.meta/config.json

@@ -17,7 +17,7 @@
       ".meta/src/example.clj"
     ]
   },
-  "blurb": "Calculate the number of steps to reach 1 using the Collatz conjecture",
+  "blurb": "Calculate the number of steps to reach 1 using the Collatz conjecture.",
   "source": "An unsolved problem in mathematics named after mathematician Lothar Collatz",
   "source_url": "https://en.wikipedia.org/wiki/3x_%2B_1_problem"
 }

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

@@ -24,6 +24,6 @@ Raising e to a complex exponent can be expressed as `e^(a + i * b) = e^a * e^(i
 Implement the following operations:
 
 - addition, subtraction, multiplication and division of two complex numbers,
-- conjugate, absolute value of a given complex number.
+- conjugate, absolute value, exponent of a given complex number.
 
 Assume the programming language you are using does not have an implementation of complex numbers.