Resync exercises (exercism#2901)

jagdish-15 · web-flow · commit a3415b951ffb · 2025-01-06T19:19:20.000+08:00
diff --git a/exercises/practice/affine-cipher/.docs/instructions.md b/exercises/practice/affine-cipher/.docs/instructions.md
@@ -4,7 +4,7 @@ Create an implementation of the affine cipher, an ancient encryption system crea
 
 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.
+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 "
 
diff --git a/exercises/practice/atbash-cipher/.docs/instructions.md b/exercises/practice/atbash-cipher/.docs/instructions.md
@@ -1,6 +1,6 @@
 # Instructions
 
-Create an implementation of the atbash cipher, an ancient encryption system created in the Middle East.
+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.
diff --git a/exercises/practice/atbash-cipher/.meta/config.json b/exercises/practice/atbash-cipher/.meta/config.json
@@ -39,7 +39,7 @@
       "build.gradle"
     ]
   },
-  "blurb": "Create an implementation of the atbash cipher, an ancient encryption system created in the Middle East.",
+  "blurb": "Create an implementation of the Atbash cipher, an ancient encryption system created in the Middle East.",
   "source": "Wikipedia",
   "source_url": "https://en.wikipedia.org/wiki/Atbash"
 }
diff --git a/exercises/practice/change/.docs/instructions.md b/exercises/practice/change/.docs/instructions.md
@@ -1,14 +1,8 @@
 # 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.
+Determine the fewest number of coins to give a customer so that the sum of their values equals the correct amount of change.
 
-## For example
+## Examples
 
-- 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
-
-- Does your algorithm work for any given set of coins?
-- Can you ask for negative change?
-- Can you ask for a change value smaller than the smallest coin value?
+- An amount of 15 with available coin values [1, 5, 10, 25, 100] should return one coin of value 5 and one coin of value 10, or [5, 10].
+- An amount of 40 with available coin values [1, 5, 10, 25, 100] should return one coin of value 5, one coin of value 10, and one coin of value 25, or [5, 10, 25].
diff --git a/exercises/practice/change/.docs/introduction.md b/exercises/practice/change/.docs/introduction.md
@@ -0,0 +1,26 @@
+# Introduction
+
+In the mystical village of Coinholt, you stand behind the counter of your bakery, arranging a fresh batch of pastries.
+The door creaks open, and in walks Denara, a skilled merchant with a keen eye for quality goods.
+After a quick meal, she slides a shimmering coin across the counter, representing a value of 100 units.
+
+You smile, taking the coin, and glance at the total cost of the meal: 88 units.
+That means you need to return 12 units in change.
+
+Denara holds out her hand expectantly.
+"Just give me the fewest coins," she says with a smile.
+"My pouch is already full, and I don't want to risk losing them on the road."
+
+You know you have a few options.
+"We have Lumis (worth 10 units), Viras (worth 5 units), and Zenth (worth 2 units) available for change."
+
+You quickly calculate the possibilities in your head:
+
+- one Lumis (1 × 10 units) + one Zenth (1 × 2 units) = 2 coins total
+- two Viras (2 × 5 units) + one Zenth (1 × 2 units) = 3 coins total
+- six Zenth (6 × 2 units) = 6 coins total
+
+"The best choice is two coins: one Lumis and one Zenth," you say, handing her the change.
+
+Denara smiles, clearly impressed.
+"As always, you've got it right."
diff --git a/exercises/practice/collatz-conjecture/.docs/instructions.md b/exercises/practice/collatz-conjecture/.docs/instructions.md
@@ -1,29 +1,3 @@
 # Instructions
 
-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.
-
-Given a number n, return the number of steps required to reach 1.
-
-## Examples
-
-Starting with n = 12, the steps would be as follows:
-
-0. 12
-1. 6
-2. 3
-3. 10
-4. 5
-5. 16
-6. 8
-7. 4
-8. 2
-9. 1
-
-Resulting in 9 steps.
-So for input n = 12, the return value would be 9.
+Given a positive integer, return the number of steps it takes to reach 1 according to the rules of the Collatz Conjecture.
diff --git a/exercises/practice/collatz-conjecture/.docs/introduction.md b/exercises/practice/collatz-conjecture/.docs/introduction.md
@@ -0,0 +1,28 @@
+# Introduction
+
+One evening, you stumbled upon an old notebook filled with cryptic scribbles, as though someone had been obsessively chasing an idea.
+On one page, a single question stood out: **Can every number find its way to 1?**
+It was tied to something called the **Collatz Conjecture**, a puzzle that has baffled thinkers for decades.
+
+The rules were deceptively simple.
+Pick any positive integer.
+
+- If it's even, divide it by 2.
+- If it's odd, multiply it by 3 and add 1.
+
+Then, repeat these steps with the result, continuing indefinitely.
+
+Curious, you picked number 12 to test and began the journey:
+
+12 ➜ 6 ➜ 3 ➜ 10 ➜ 5 ➜ 16 ➜ 8 ➜ 4 ➜ 2 ➜ 1
+
+Counting from the second number (6), it took 9 steps to reach 1, and each time the rules repeated, the number kept changing.
+At first, the sequence seemed unpredictable — jumping up, down, and all over.
+Yet, the conjecture claims that no matter the starting number, we'll always end at 1.
+
+It was fascinating, but also puzzling.
+Why does this always seem to work?
+Could there be a number where the process breaks down, looping forever or escaping into infinity?
+The notebook suggested solving this could reveal something profound — and with it, fame, [fortune][collatz-prize], and a place in history awaits whoever could unlock its secrets.
+
+[collatz-prize]: https://mathprize.net/posts/collatz-conjecture/
diff --git a/exercises/practice/collatz-conjecture/.meta/config.json b/exercises/practice/collatz-conjecture/.meta/config.json
@@ -35,6 +35,6 @@
     ]
   },
   "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"
+  "source": "Wikipedia",
+  "source_url": "https://en.wikipedia.org/wiki/Collatz_conjecture"
 }
diff --git a/exercises/practice/dominoes/.docs/instructions.md b/exercises/practice/dominoes/.docs/instructions.md
@@ -2,7 +2,9 @@
 
 Make a chain of dominoes.
 
-Compute a way to order a given set of dominoes in such a way that they form a correct domino chain (the dots on one half of a stone match the dots on the neighboring half of an adjacent stone) and that dots on the halves of the stones which don't have a neighbor (the first and last stone) match each other.
+Compute a way to order a given set of domino stones so that they form a correct domino chain.
+In the chain, the dots on one half of a stone must match the dots on the neighboring half of an adjacent stone.
+Additionally, the dots on the halves of the stones without neighbors (the first and last stone) must match each other.
 
 For example given the stones `[2|1]`, `[2|3]` and `[1|3]` you should compute something
 like `[1|2] [2|3] [3|1]` or `[3|2] [2|1] [1|3]` or `[1|3] [3|2] [2|1]` etc, where the first and last numbers are the same.
diff --git a/exercises/practice/dominoes/.docs/introduction.md b/exercises/practice/dominoes/.docs/introduction.md
@@ -0,0 +1,13 @@
+# Introduction
+
+In Toyland, the trains are always busy delivering treasures across the city, from shiny marbles to rare building blocks.
+The tracks they run on are made of colorful domino-shaped pieces, each marked with two numbers.
+For the trains to move, the dominoes must form a perfect chain where the numbers match.
+
+Today, an urgent delivery of rare toys is on hold.
+You've been handed a set of track pieces to inspect.
+If they can form a continuous chain, the train will be on its way, bringing smiles across Toyland.
+If not, the set will be discarded, and another will be tried.
+
+The toys are counting on you to solve this puzzle.
+Will the dominoes connect the tracks and send the train rolling, or will the set be left behind?
diff --git a/exercises/practice/eliuds-eggs/.docs/introduction.md b/exercises/practice/eliuds-eggs/.docs/introduction.md
@@ -12,36 +12,54 @@ The position information encoding is calculated as follows:
 2. Convert the number from binary to decimal.
 3. Show the result on the display.
 
-Example 1:
+## Example 1
+
+![Seven individual nest boxes arranged in a row whose first, third, fourth and seventh nests each have a single egg.](https://assets.exercism.org/images/exercises/eliuds-eggs/example-1-coop.svg)
 
 ```text
-Chicken Coop:
  _ _ _ _ _ _ _
 |E| |E|E| | |E|
+```
+
+### Resulting Binary
+
+![1011001](https://assets.exercism.org/images/exercises/eliuds-eggs/example-1-binary.svg)
+
+```text
+ _ _ _ _ _ _ _
+|1|0|1|1|0|0|1|
+```
 
-Resulting Binary:
- 1 0 1 1 0 0 1
+### Decimal number on the display
 
-Decimal number on the display:
 89
 
-Actual eggs in the coop:
+### Actual eggs in the coop
+
 4
+
+## Example 2
+
+![Seven individual nest boxes arranged in a row where only the fourth nest has an egg.](https://assets.exercism.org/images/exercises/eliuds-eggs/example-2-coop.svg)
+
+```text
+ _ _ _ _ _ _ _
+| | | |E| | | |
 ```
 
-Example 2:
+### Resulting Binary
+
+![0001000](https://assets.exercism.org/images/exercises/eliuds-eggs/example-2-binary.svg)
 
 ```text
-Chicken Coop:
- _ _ _ _ _ _ _ _
-| | | |E| | | | |
+ _ _ _ _ _ _ _
+|0|0|0|1|0|0|0|
+```
 
-Resulting Binary:
- 0 0 0 1 0 0 0 0
+### Decimal number on the display
 
-Decimal number on the display:
 16
 
-Actual eggs in the coop:
+### Actual eggs in the coop
+
 1
-```
diff --git a/exercises/practice/grade-school/.docs/instructions.md b/exercises/practice/grade-school/.docs/instructions.md
@@ -1,21 +1,21 @@
 # Instructions
 
-Given students' names along with the grade that they are in, create a roster for the school.
+Given students' names along with the grade they are in, create a roster for the school.
 
 In the end, you should be able to:
 
-- Add a student's name to the roster for a grade
+- Add a student's name to the roster for a grade:
   - "Add Jim to grade 2."
   - "OK."
-- Get a list of all students enrolled in a grade
+- Get a list of all students enrolled in a grade:
   - "Which students are in grade 2?"
-  - "We've only got Jim just now."
+  - "We've only got Jim right now."
 - Get a sorted list of all students in all grades.
-  Grades should sort as 1, 2, 3, etc., and students within a grade should be sorted alphabetically by name.
-  - "Who all is enrolled in school right now?"
+  Grades should be sorted as 1, 2, 3, etc., and students within a grade should be sorted alphabetically by name.
+  - "Who is enrolled in school right now?"
   - "Let me think.
-    We have Anna, Barb, and Charlie in grade 1, Alex, Peter, and Zoe in grade 2 and Jim in grade 5.
-    So the answer is: Anna, Barb, Charlie, Alex, Peter, Zoe and Jim"
+    We have Anna, Barb, and Charlie in grade 1, Alex, Peter, and Zoe in grade 2, and Jim in grade 5.
+    So the answer is: Anna, Barb, Charlie, Alex, Peter, Zoe, and Jim."
 
-Note that all our students only have one name (It's a small town, what do you want?) and each student cannot be added more than once to a grade or the roster.
-In fact, when a test attempts to add the same student more than once, your implementation should indicate that this is incorrect.
+Note that all our students only have one name (it's a small town, what do you want?), and each student cannot be added more than once to a grade or the roster.
+If a test attempts to add the same student more than once, your implementation should indicate that this is incorrect.
diff --git a/exercises/practice/hamming/.docs/instructions.md b/exercises/practice/hamming/.docs/instructions.md
@@ -2,15 +2,6 @@
 
 Calculate the Hamming distance between two DNA strands.
 
-Your body is made up of cells that contain DNA.
-Those cells regularly wear out and need replacing, which they achieve by dividing into daughter cells.
-In fact, the average human body experiences about 10 quadrillion cell divisions in a lifetime!
-
-When cells divide, their DNA replicates too.
-Sometimes during this process mistakes happen and single pieces of DNA get encoded with the incorrect information.
-If we compare two strands of DNA and count the differences between them we can see how many mistakes occurred.
-This is known as the "Hamming distance".
-
 We read DNA using the letters C, A, G and T.
 Two strands might look like this:
 
@@ -20,8 +11,6 @@ Two strands might look like this:
 
 They have 7 differences, and therefore the Hamming distance is 7.
 
-The Hamming distance is useful for lots of things in science, not just biology, so it's a nice phrase to be familiar with :)
-
 ## Implementation notes
 
 The Hamming distance is only defined for sequences of equal length, so an attempt to calculate it between sequences of different lengths should not work.
diff --git a/exercises/practice/hamming/.docs/introduction.md b/exercises/practice/hamming/.docs/introduction.md
@@ -0,0 +1,12 @@
+# Introduction
+
+Your body is made up of cells that contain DNA.
+Those cells regularly wear out and need replacing, which they achieve by dividing into daughter cells.
+In fact, the average human body experiences about 10 quadrillion cell divisions in a lifetime!
+
+When cells divide, their DNA replicates too.
+Sometimes during this process mistakes happen and single pieces of DNA get encoded with the incorrect information.
+If we compare two strands of DNA and count the differences between them, we can see how many mistakes occurred.
+This is known as the "Hamming distance".
+
+The Hamming distance is useful in many areas of science, not just biology, so it's a nice phrase to be familiar with :)
diff --git a/exercises/practice/knapsack/.docs/instructions.md b/exercises/practice/knapsack/.docs/instructions.md
@@ -1,11 +1,11 @@
 # Instructions
 
-Your task is to determine which items to take so that the total value of his selection is maximized, taking into account the knapsack's carrying capacity.
+Your task is to determine which items to take so that the total value of her selection is maximized, taking into account the knapsack's carrying capacity.
 
 Items will be represented as a list of items.
 Each item will have a weight and value.
 All values given will be strictly positive.
-Bob can take only one of each item.
+Lhakpa can take only one of each item.
 
 For example:
 
@@ -21,5 +21,5 @@ Knapsack Maximum Weight: 10
 ```
 
 For the above, the first item has weight 5 and value 10, the second item has weight 4 and value 40, and so on.
-In this example, Bob should take the second and fourth item to maximize his value, which, in this case, is 90.
-He cannot get more than 90 as his knapsack has a weight limit of 10.
+In this example, Lhakpa should take the second and fourth item to maximize her value, which, in this case, is 90.
+She cannot get more than 90 as her knapsack has a weight limit of 10.
diff --git a/exercises/practice/knapsack/.docs/introduction.md b/exercises/practice/knapsack/.docs/introduction.md
@@ -1,8 +1,10 @@
 # Introduction
 
-Bob is a thief.
-After months of careful planning, he finally manages to crack the security systems of a fancy store.
+Lhakpa is a [Sherpa][sherpa] mountain guide and porter.
+After months of careful planning, the expedition Lhakpa works for is about to leave.
+She will be paid the value she carried to the base camp.
 
-In front of him are many items, each with a value and weight.
-Bob would gladly take all of the items, but his knapsack can only hold so much weight.
-Bob has to carefully consider which items to take so that the total value of his selection is maximized.
+In front of her are many items, each with a value and weight.
+Lhakpa would gladly take all of the items, but her knapsack can only hold so much weight.
+
+[sherpa]: https://en.wikipedia.org/wiki/Sherpa_people#Mountaineering
diff --git a/exercises/practice/luhn/.docs/instructions.md b/exercises/practice/luhn/.docs/instructions.md
@@ -1,12 +1,10 @@
 # Instructions
 
-Given a number determine whether or not it is valid per the Luhn formula.
+Determine whether a credit card number is valid according to the [Luhn formula][luhn].
 
-The [Luhn algorithm][luhn] is a simple checksum formula used to validate a variety of identification numbers, such as credit card numbers and Canadian Social Insurance Numbers.
+The number will be provided as a string.
 
-The task is to check if a given string is valid.
-
-## Validating a Number
+## Validating a number
 
 Strings of length 1 or less are not valid.
 Spaces are allowed in the input, but they should be stripped before checking.
diff --git a/exercises/practice/luhn/.docs/introduction.md b/exercises/practice/luhn/.docs/introduction.md
@@ -0,0 +1,11 @@
+# Introduction
+
+At the Global Verification Authority, you've just been entrusted with a critical assignment.
+Across the city, from online purchases to secure logins, countless operations rely on the accuracy of numerical identifiers like credit card numbers, bank account numbers, transaction codes, and tracking IDs.
+The Luhn algorithm is a simple checksum formula used to ensure these numbers are valid and error-free.
+
+A batch of identifiers has just arrived on your desk.
+All of them must pass the Luhn test to ensure they're legitimate.
+If any fail, they'll be flagged as invalid, preventing errors or fraud, such as incorrect transactions or unauthorized access.
+
+Can you ensure this is done right? The integrity of many services depends on you.
diff --git a/exercises/practice/pascals-triangle/.docs/introduction.md b/exercises/practice/pascals-triangle/.docs/introduction.md
@@ -13,7 +13,7 @@ Over the next hour, your teacher reveals some amazing things hidden in this tria
 - It contains the Fibonacci sequence.
 - If you color odd and even numbers differently, you get a beautiful pattern called the [Sierpiński triangle][wikipedia-sierpinski-triangle].
 
-The teacher implores you and your classmates to lookup other uses, and assures you that there are lots more!
+The teacher implores you and your classmates to look up other uses, and assures you that there are lots more!
 At that moment, the school bell rings.
 You realize that for the past hour, you were completely absorbed in learning about Pascal's triangle.
 You quickly grab your laptop from your bag and go outside, ready to enjoy both the sunshine _and_ the wonders of Pascal's triangle.
diff --git a/exercises/practice/phone-number/.docs/introduction.md b/exercises/practice/phone-number/.docs/introduction.md
@@ -0,0 +1,12 @@
+# Introduction
+
+You've joined LinkLine, a leading communications company working to ensure reliable connections for everyone.
+The team faces a big challenge: users submit phone numbers in all sorts of formats — dashes, spaces, dots, parentheses, and even prefixes.
+Some numbers are valid, while others are impossible to use.
+
+Your mission is to turn this chaos into order.
+You'll clean up valid numbers, formatting them appropriately for use in the system.
+At the same time, you'll identify and filter out any invalid entries.
+
+The success of LinkLine's operations depends on your ability to separate the useful from the unusable.
+Are you ready to take on the challenge and keep the connections running smoothly?
diff --git a/exercises/practice/pythagorean-triplet/.docs/instructions.md b/exercises/practice/pythagorean-triplet/.docs/instructions.md
@@ -1,4 +1,4 @@
-# Instructions
+# Description
 
 A Pythagorean triplet is a set of three natural numbers, {a, b, c}, for which,
 
diff --git a/exercises/practice/pythagorean-triplet/.docs/introduction.md b/exercises/practice/pythagorean-triplet/.docs/introduction.md

Original file line number	Diff line number	Diff line change
`@@ -39,7 +39,7 @@`
`39`	`39`	`"build.gradle"`
`40`	`40`	`]`
`41`	`41`	`},`
`42`		`- "blurb": "Create an implementation of the atbash cipher, an ancient encryption system created in the Middle East.",`
	`42`	`+ "blurb": "Create an implementation of the Atbash cipher, an ancient encryption system created in the Middle East.",`
`43`	`43`	`"source": "Wikipedia",`
`44`	`44`	`"source_url": "https://en.wikipedia.org/wiki/Atbash"`
`45`	`45`	`}`
Original file line number	Diff line number	Diff line change
`@@ -35,6 +35,6 @@`
`35`	`35`	`]`
`36`	`36`	`},`
`37`	`37`	`"blurb": "Calculate the number of steps to reach 1 using the Collatz conjecture.",`
`38`		`- "source": "An unsolved problem in mathematics named after mathematician Lothar Collatz",`
`39`		`- "source_url": "https://en.wikipedia.org/wiki/3x_%2B_1_problem"`
	`38`	`+ "source": "Wikipedia",`
	`39`	`+ "source_url": "https://en.wikipedia.org/wiki/Collatz_conjecture"`
`40`	`40`	`}`