diff --git a/exercises/practice/affine-cipher/.docs/instructions.md b/exercises/practice/affine-cipher/.docs/instructions.md index 4eff918d..1603dbbc 100644 --- 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 " @@ -20,7 +20,7 @@ Where: - `i` is the letter's index from `0` to the length of the alphabet - 1. - `m` is the length of the alphabet. - For the Roman alphabet `m` is `26`. + For the Latin alphabet `m` is `26`. - `a` and `b` are integers which make up 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]). diff --git a/exercises/practice/anagram/.docs/instructions.md b/exercises/practice/anagram/.docs/instructions.md index a7298485..dca24f52 100644 --- a/exercises/practice/anagram/.docs/instructions.md +++ b/exercises/practice/anagram/.docs/instructions.md @@ -1,13 +1,12 @@ # 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. +Given a target word and one or more candidate words, your task is to find 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"`. -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`. -The anagram set is the subset of the candidate set that are anagrams of the target (in any order). -Words in the anagram set should have the same letter case as in the candidate set. +The target word and candidate words are made up 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"`. +The words you need to find should be taken from the candidate words, using the same letter case. -Given the target `"stone"` and candidates `"stone"`, `"tones"`, `"banana"`, `"tons"`, `"notes"`, `"Seton"`, the anagram set is `"tones"`, `"notes"`, `"Seton"`. +Given the target `"stone"` and the candidate words `"stone"`, `"tones"`, `"banana"`, `"tons"`, `"notes"`, and `"Seton"`, the anagram words you need to find are `"tones"`, `"notes"`, and `"Seton"`. diff --git a/exercises/practice/atbash-cipher/.docs/instructions.md b/exercises/practice/atbash-cipher/.docs/instructions.md index 21ca2ce0..1e7627b1 100644 --- 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 index b0bdd273..a4803c44 100644 --- a/exercises/practice/atbash-cipher/.meta/config.json +++ b/exercises/practice/atbash-cipher/.meta/config.json @@ -13,7 +13,7 @@ ".meta/AtbashCipher.example.ps1" ] }, - "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 index 30fa5677..5887f4cb 100644 --- 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 new file mode 100644 index 00000000..b4f8308a --- /dev/null +++ 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 index ba060483..af332a81 100644 --- 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 new file mode 100644 index 00000000..c35bdeb6 --- /dev/null +++ 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 index d2738823..2f371286 100644 --- a/exercises/practice/collatz-conjecture/.meta/config.json +++ b/exercises/practice/collatz-conjecture/.meta/config.json @@ -14,6 +14,6 @@ ] }, "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/complex-numbers/.docs/instructions.md b/exercises/practice/complex-numbers/.docs/instructions.md index 50b19aed..2b8a7a49 100644 --- a/exercises/practice/complex-numbers/.docs/instructions.md +++ b/exercises/practice/complex-numbers/.docs/instructions.md @@ -1,29 +1,100 @@ # Instructions -A complex number is a number in the form `a + b * i` where `a` and `b` are real and `i` satisfies `i^2 = -1`. +A **complex number** is expressed in the form `z = a + b * i`, where: -`a` is called the real part and `b` is called the imaginary part of `z`. -The conjugate of the number `a + b * i` is the number `a - b * i`. -The absolute value of a complex number `z = a + b * i` is a real number `|z| = sqrt(a^2 + b^2)`. The square of the absolute value `|z|^2` is the result of multiplication of `z` by its complex conjugate. +- `a` is the **real part** (a real number), -The sum/difference of two complex numbers involves adding/subtracting their real and imaginary parts separately: -`(a + i * b) + (c + i * d) = (a + c) + (b + d) * i`, -`(a + i * b) - (c + i * d) = (a - c) + (b - d) * i`. +- `b` is the **imaginary part** (also a real number), and -Multiplication result is by definition -`(a + i * b) * (c + i * d) = (a * c - b * d) + (b * c + a * d) * i`. +- `i` is the **imaginary unit** satisfying `i^2 = -1`. -The reciprocal of a non-zero complex number is -`1 / (a + i * b) = a/(a^2 + b^2) - b/(a^2 + b^2) * i`. +## Operations on Complex Numbers -Dividing a complex number `a + i * b` by another `c + i * d` gives: -`(a + i * b) / (c + i * d) = (a * c + b * d)/(c^2 + d^2) + (b * c - a * d)/(c^2 + d^2) * i`. +### Conjugate -Raising e to a complex exponent can be expressed as `e^(a + i * b) = e^a * e^(i * b)`, the last term of which is given by Euler's formula `e^(i * b) = cos(b) + i * sin(b)`. +The conjugate of the complex number `z = a + b * i` is given by: -Implement the following operations: +```text +zc = a - b * i +``` -- addition, subtraction, multiplication and division of two complex numbers, -- conjugate, absolute value, exponent of a given complex number. +### Absolute Value -Assume the programming language you are using does not have an implementation of complex numbers. +The absolute value (or modulus) of `z` is defined as: + +```text +|z| = sqrt(a^2 + b^2) +``` + +The square of the absolute value is computed as the product of `z` and its conjugate `zc`: + +```text +|z|^2 = z * zc = a^2 + b^2 +``` + +### Addition + +The sum of two complex numbers `z1 = a + b * i` and `z2 = c + d * i` is computed by adding their real and imaginary parts separately: + +```text +z1 + z2 = (a + b * i) + (c + d * i) + = (a + c) + (b + d) * i +``` + +### Subtraction + +The difference of two complex numbers is obtained by subtracting their respective parts: + +```text +z1 - z2 = (a + b * i) - (c + d * i) + = (a - c) + (b - d) * i +``` + +### Multiplication + +The product of two complex numbers is defined as: + +```text +z1 * z2 = (a + b * i) * (c + d * i) + = (a * c - b * d) + (b * c + a * d) * i +``` + +### Reciprocal + +The reciprocal of a non-zero complex number is given by: + +```text +1 / z = 1 / (a + b * i) + = a / (a^2 + b^2) - b / (a^2 + b^2) * i +``` + +### Division + +The division of one complex number by another is given by: + +```text +z1 / z2 = z1 * (1 / z2) + = (a + b * i) / (c + d * i) + = (a * c + b * d) / (c^2 + d^2) + (b * c - a * d) / (c^2 + d^2) * i +``` + +### Exponentiation + +Raising _e_ (the base of the natural logarithm) to a complex exponent can be expressed using Euler's formula: + +```text +e^(a + b * i) = e^a * e^(b * i) + = e^a * (cos(b) + i * sin(b)) +``` + +## Implementation Requirements + +Given that you should not use built-in support for complex numbers, implement the following operations: + +- **addition** of two complex numbers +- **subtraction** of two complex numbers +- **multiplication** of two complex numbers +- **division** of two complex numbers +- **conjugate** of a complex number +- **absolute value** of a complex number +- **exponentiation** of _e_ (the base of the natural logarithm) to a complex number diff --git a/exercises/practice/dominoes/.docs/instructions.md b/exercises/practice/dominoes/.docs/instructions.md index 1ced9f64..75055b9e 100644 --- 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 new file mode 100644 index 00000000..df248c21 --- /dev/null +++ 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 index 49eaffd8..81989748 100644 --- 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/flatten-array/.docs/instructions.md b/exercises/practice/flatten-array/.docs/instructions.md index 89dacfa3..b5b82713 100644 --- a/exercises/practice/flatten-array/.docs/instructions.md +++ b/exercises/practice/flatten-array/.docs/instructions.md @@ -1,11 +1,16 @@ # Instructions -Take a nested list and return a single flattened list with all values except nil/null. +Take a nested array of any depth and return a fully flattened array. -The challenge is to take an arbitrarily-deep nested list-like structure and produce a flattened structure without any nil/null values. +Note that some language tracks may include null-like values in the input array, and the way these values are represented varies by track. +Such values should be excluded from the flattened array. -For example: +Additionally, the input may be of a different data type and contain different types, depending on the track. -input: [1,[2,3,null,4],[null],5] +Check the test suite for details. -output: [1,2,3,4,5] +## Example + +input: `[1, [2, 6, null], [[null, [4]], 5]]` + +output: `[1, 2, 6, 4, 5]` diff --git a/exercises/practice/flatten-array/.docs/introduction.md b/exercises/practice/flatten-array/.docs/introduction.md new file mode 100644 index 00000000..a3148574 --- /dev/null +++ b/exercises/practice/flatten-array/.docs/introduction.md @@ -0,0 +1,7 @@ +# Introduction + +A shipment of emergency supplies has arrived, but there's a problem. +To protect from damage, the items — flashlights, first-aid kits, blankets — are packed inside boxes, and some of those boxes are nested several layers deep inside other boxes! + +To be prepared for an emergency, everything must be easily accessible in one box. +Can you unpack all the supplies and place them into a single box, so they're ready when needed most? diff --git a/exercises/practice/grade-school/.docs/instructions.md b/exercises/practice/grade-school/.docs/instructions.md index 9a63e398..3cb1b5d5 100644 --- 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/grains/.docs/instructions.md b/exercises/practice/grains/.docs/instructions.md index df479fc0..f5b752a8 100644 --- a/exercises/practice/grains/.docs/instructions.md +++ b/exercises/practice/grains/.docs/instructions.md @@ -1,15 +1,11 @@ # Instructions -Calculate the number of grains of wheat on a chessboard given that the number on each square doubles. +Calculate the number of grains of wheat on a chessboard. -There once was a wise servant who saved the life of a prince. -The king promised to pay whatever the servant could dream up. -Knowing that the king loved chess, the servant told the king he would like to have grains of wheat. -One grain on the first square of a chess board, with the number of grains doubling on each successive square. +A chessboard has 64 squares. +Square 1 has one grain, square 2 has two grains, square 3 has four grains, and so on, doubling each time. -There are 64 squares on a chessboard (where square 1 has one grain, square 2 has two grains, and so on). +Write code that calculates: -Write code that shows: - -- how many grains were on a given square, and +- the number of grains on a given square - the total number of grains on the chessboard diff --git a/exercises/practice/grains/.docs/introduction.md b/exercises/practice/grains/.docs/introduction.md new file mode 100644 index 00000000..0df4f46f --- /dev/null +++ b/exercises/practice/grains/.docs/introduction.md @@ -0,0 +1,6 @@ +# Introduction + +There once was a wise servant who saved the life of a prince. +The king promised to pay whatever the servant could dream up. +Knowing that the king loved chess, the servant told the king he would like to have grains of wheat. +One grain on the first square of a chessboard, with the number of grains doubling on each successive square. diff --git a/exercises/practice/grains/.meta/config.json b/exercises/practice/grains/.meta/config.json index c2a4427a..b1e91adc 100644 --- a/exercises/practice/grains/.meta/config.json +++ b/exercises/practice/grains/.meta/config.json @@ -1,5 +1,7 @@ { - "authors": ["meatball133"], + "authors": [ + "meatball133" + ], "files": { "solution": [ "Grains.ps1" @@ -13,5 +15,5 @@ }, "blurb": "Calculate the number of grains of wheat on a chessboard given that the number on each square doubles.", "source": "The CodeRanch Cattle Drive, Assignment 6", - "source_url": "https://coderanch.com/wiki/718824/Grains" + "source_url": "https://web.archive.org/web/20240908084142/https://coderanch.com/wiki/718824/Grains" } diff --git a/exercises/practice/hamming/.docs/instructions.md b/exercises/practice/hamming/.docs/instructions.md index 020fdd02..8f47a179 100644 --- a/exercises/practice/hamming/.docs/instructions.md +++ b/exercises/practice/hamming/.docs/instructions.md @@ -1,26 +1,15 @@ # Instructions -Calculate the Hamming Distance between two DNA strands. +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. +We read DNA using the letters C, A, G and T. Two strands might look like this: GAGCCTACTAACGGGAT CATCGTAATGACGGCCT ^ ^ ^ ^ ^ ^^ -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 :) +They have 7 differences, and therefore the Hamming distance is 7. ## Implementation notes diff --git a/exercises/practice/hamming/.docs/introduction.md b/exercises/practice/hamming/.docs/introduction.md new file mode 100644 index 00000000..8419bf47 --- /dev/null +++ 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/hamming/.meta/config.json b/exercises/practice/hamming/.meta/config.json index 749ffa6e..6c6799fa 100644 --- a/exercises/practice/hamming/.meta/config.json +++ b/exercises/practice/hamming/.meta/config.json @@ -22,7 +22,7 @@ ".meta/HammingDifference.example.ps1" ] }, - "blurb": "Calculate the Hamming difference between two DNA strands.", + "blurb": "Calculate the Hamming distance between two DNA strands.", "source": "The Calculating Point Mutations problem at Rosalind", "source_url": "https://rosalind.info/problems/hamm/" } diff --git a/exercises/practice/knapsack/.docs/instructions.md b/exercises/practice/knapsack/.docs/instructions.md index 3411db98..0ebf7914 100644 --- 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 index 9b2bed8b..9ac9df59 100644 --- 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/leap/.meta/config.json b/exercises/practice/leap/.meta/config.json index 285016a2..ddb5557f 100644 --- a/exercises/practice/leap/.meta/config.json +++ b/exercises/practice/leap/.meta/config.json @@ -20,5 +20,5 @@ }, "blurb": "Determine whether a given year is a leap year.", "source": "CodeRanch Cattle Drive, Assignment 3", - "source_url": "https://coderanch.com/t/718816/Leap" + "source_url": "https://web.archive.org/web/20240907033714/https://coderanch.com/t/718816/Leap" } diff --git a/exercises/practice/luhn/.docs/instructions.md b/exercises/practice/luhn/.docs/instructions.md index 8cbe791f..5bbf007b 100644 --- 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. @@ -22,7 +20,8 @@ The first step of the Luhn algorithm is to double every second digit, starting f We will be doubling ```text -4_3_ 3_9_ 0_4_ 6_6_ +4539 3195 0343 6467 +↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ (double these) ``` If doubling the number results in a number greater than 9 then subtract 9 from the product. diff --git a/exercises/practice/luhn/.docs/introduction.md b/exercises/practice/luhn/.docs/introduction.md new file mode 100644 index 00000000..ec2bd709 --- /dev/null +++ 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 index 60b8ec30..eab454e5 100644 --- 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 new file mode 100644 index 00000000..c4142c5a --- /dev/null +++ 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/pov/.meta/config.json b/exercises/practice/pov/.meta/config.json index 5bd7135c..de9341b8 100644 --- a/exercises/practice/pov/.meta/config.json +++ b/exercises/practice/pov/.meta/config.json @@ -15,5 +15,5 @@ }, "blurb": "Reparent a graph on a selected node.", "source": "Adaptation of exercise from 4clojure", - "source_url": "https://www.4clojure.com/" + "source_url": "https://github.com/oxalorg/4ever-clojure" } diff --git a/exercises/practice/protein-translation/.docs/instructions.md b/exercises/practice/protein-translation/.docs/instructions.md index 7dc34d2e..44880802 100644 --- a/exercises/practice/protein-translation/.docs/instructions.md +++ b/exercises/practice/protein-translation/.docs/instructions.md @@ -2,12 +2,12 @@ Translate RNA sequences into proteins. -RNA can be broken into three nucleotide sequences called codons, and then translated to a polypeptide like so: +RNA can be broken into three-nucleotide sequences called codons, and then translated to a protein like so: RNA: `"AUGUUUUCU"` => translates to Codons: `"AUG", "UUU", "UCU"` -=> which become a polypeptide with the following sequence => +=> which become a protein with the following sequence => Protein: `"Methionine", "Phenylalanine", "Serine"` @@ -27,9 +27,9 @@ 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. +Below are the codons and resulting amino acids needed for the exercise. -| Codon | Protein | +| Codon | Amino Acid | | :----------------- | :------------ | | AUG | Methionine | | UUU, UUC | Phenylalanine | diff --git a/exercises/practice/pythagorean-triplet/.docs/instructions.md b/exercises/practice/pythagorean-triplet/.docs/instructions.md index 1c1a8aea..ced833d7 100644 --- 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 new file mode 100644 index 00000000..3453c6ed --- /dev/null +++ b/exercises/practice/pythagorean-triplet/.docs/introduction.md @@ -0,0 +1,19 @@ +# Introduction + +You are an accomplished problem-solver, known for your ability to tackle the most challenging mathematical puzzles. +One evening, you receive an urgent letter from an inventor called the Triangle Tinkerer, who is working on a groundbreaking new project. +The letter reads: + +> Dear Mathematician, +> +> I need your help. +> I am designing a device that relies on the unique properties of Pythagorean triplets — sets of three integers that satisfy the equation a² + b² = c². +> This device will revolutionize navigation, but for it to work, I must program it with every possible triplet where the sum of a, b, and c equals a specific number, N. +> Calculating these triplets by hand would take me years, but I hear you are more than up to the task. +> +> Time is of the essence. +> The future of my invention — and perhaps even the future of mathematical innovation — rests on your ability to solve this problem. + +Motivated by the importance of the task, you set out to find all Pythagorean triplets that satisfy the condition. +Your work could have far-reaching implications, unlocking new possibilities in science and engineering. +Can you rise to the challenge and make history? diff --git a/exercises/practice/pythagorean-triplet/.meta/config.json b/exercises/practice/pythagorean-triplet/.meta/config.json index 78fa451a..17d3a6ca 100644 --- a/exercises/practice/pythagorean-triplet/.meta/config.json +++ b/exercises/practice/pythagorean-triplet/.meta/config.json @@ -13,7 +13,7 @@ ".meta/PythagoreanTriplet.example.ps1" ] }, - "blurb": "There exists exactly one Pythagorean triplet for which a + b + c = 1000. Find the triplet.", - "source": "Problem 9 at Project Euler", + "blurb": "Given an integer N, find all Pythagorean triplets for which a + b + c = N.", + "source": "A variation of Problem 9 from Project Euler", "source_url": "https://projecteuler.net/problem=9" } diff --git a/exercises/practice/rna-transcription/.docs/instructions.md b/exercises/practice/rna-transcription/.docs/instructions.md index 36da381f..4dbfd3a2 100644 --- a/exercises/practice/rna-transcription/.docs/instructions.md +++ b/exercises/practice/rna-transcription/.docs/instructions.md @@ -1,12 +1,12 @@ # Instructions -Your task is determine the RNA complement of a given DNA sequence. +Your task is to determine the RNA complement of a given DNA sequence. Both DNA and RNA strands are a sequence of nucleotides. -The four nucleotides found in DNA are adenine (**A**), cytosine (**C**), guanine (**G**) and thymine (**T**). +The four nucleotides found in DNA are adenine (**A**), cytosine (**C**), guanine (**G**), and thymine (**T**). -The four nucleotides found in RNA are adenine (**A**), cytosine (**C**), guanine (**G**) and uracil (**U**). +The four nucleotides found in RNA are adenine (**A**), cytosine (**C**), guanine (**G**), and uracil (**U**). Given a DNA strand, its transcribed RNA strand is formed by replacing each nucleotide with its complement: diff --git a/exercises/practice/rna-transcription/.meta/config.json b/exercises/practice/rna-transcription/.meta/config.json index f3d2788d..f0279a31 100644 --- a/exercises/practice/rna-transcription/.meta/config.json +++ b/exercises/practice/rna-transcription/.meta/config.json @@ -1,5 +1,7 @@ { - "authors": ["meatball133"], + "authors": [ + "meatball133" + ], "files": { "solution": [ "RnaTranscription.ps1" @@ -11,7 +13,7 @@ ".meta/RnaTranscription.example.ps1" ] }, - "blurb": "Given a DNA strand, return its RNA Complement Transcription.", + "blurb": "Given a DNA strand, return its RNA complement.", "source": "Hyperphysics", "source_url": "https://web.archive.org/web/20220408112140/http://hyperphysics.phy-astr.gsu.edu/hbase/Organic/transcription.html" } diff --git a/exercises/practice/saddle-points/.docs/instructions.md b/exercises/practice/saddle-points/.docs/instructions.md index c585568b..f69cdab9 100644 --- a/exercises/practice/saddle-points/.docs/instructions.md +++ b/exercises/practice/saddle-points/.docs/instructions.md @@ -13,11 +13,12 @@ Or it might have one, or even several. Here is a grid that has exactly one candidate tree. ```text - 1 2 3 4 - |----------- -1 | 9 8 7 8 -2 | 5 3 2 4 <--- potential tree house at row 2, column 1, for tree with height 5 -3 | 6 6 7 1 + ↓ + 1 2 3 4 + |----------- + 1 | 9 8 7 8 +→ 2 |[5] 3 2 4 + 3 | 6 6 7 1 ``` - Row 2 has values 5, 3, 2, and 4. The largest value is 5. diff --git a/exercises/practice/say/.meta/config.json b/exercises/practice/say/.meta/config.json index 1bdeaa1b..af770000 100644 --- a/exercises/practice/say/.meta/config.json +++ b/exercises/practice/say/.meta/config.json @@ -15,5 +15,5 @@ }, "blurb": "Given a number from 0 to 999,999,999,999, spell out that number in English.", "source": "A variation on the JavaRanch CattleDrive, Assignment 4", - "source_url": "https://coderanch.com/wiki/718804" + "source_url": "https://web.archive.org/web/20240907035912/https://coderanch.com/wiki/718804" } diff --git a/exercises/practice/sieve/.docs/instructions.md b/exercises/practice/sieve/.docs/instructions.md index 085c0a57..71292e17 100644 --- a/exercises/practice/sieve/.docs/instructions.md +++ b/exercises/practice/sieve/.docs/instructions.md @@ -6,37 +6,96 @@ A prime number is a number larger than 1 that is only divisible by 1 and itself. For example, 2, 3, 5, 7, 11, and 13 are prime numbers. By contrast, 6 is _not_ a prime number as it not only divisible by 1 and itself, but also by 2 and 3. -To use the Sieve of Eratosthenes, you first create a list of all the numbers between 2 and your given number. -Then you repeat the following steps: +To use the Sieve of Eratosthenes, first, write out all the numbers from 2 up to and including your given number. +Then, follow these steps: -1. Find the next unmarked number in your list (skipping over marked numbers). +1. Find the next unmarked number (skipping over marked numbers). This is a prime number. 2. Mark all the multiples of that prime number as **not** prime. -You keep repeating these steps until you've gone through every number in your list. +Repeat the steps until you've gone through every number. At the end, all the unmarked numbers are prime. ~~~~exercism/note -The tests don't check that you've implemented the algorithm, only that you've come up with the correct list of primes. -To check you are implementing the Sieve correctly, a good first test is to check that you do not use division or remainder operations. +The Sieve of Eratosthenes marks off multiples of each prime using addition (repeatedly adding the prime) or multiplication (directly computing its multiples), rather than checking each number for divisibility. + +The tests don't check that you've implemented the algorithm, only that you've come up with the correct primes. ~~~~ ## Example Let's say you're finding the primes less than or equal to 10. -- List out 2, 3, 4, 5, 6, 7, 8, 9, 10, leaving them all unmarked. +- Write out 2, 3, 4, 5, 6, 7, 8, 9, 10, leaving them all unmarked. + + ```text + 2 3 4 5 6 7 8 9 10 + ``` + - 2 is unmarked and is therefore a prime. Mark 4, 6, 8 and 10 as "not prime". + + ```text + 2 3 [4] 5 [6] 7 [8] 9 [10] + ↑ + ``` + - 3 is unmarked and is therefore a prime. Mark 6 and 9 as not prime _(marking 6 is optional - as it's already been marked)_. + + ```text + 2 3 [4] 5 [6] 7 [8] [9] [10] + ↑ + ``` + - 4 is marked as "not prime", so we skip over it. + + ```text + 2 3 [4] 5 [6] 7 [8] [9] [10] + ↑ + ``` + - 5 is unmarked and is therefore a prime. Mark 10 as not prime _(optional - as it's already been marked)_. + + ```text + 2 3 [4] 5 [6] 7 [8] [9] [10] + ↑ + ``` + - 6 is marked as "not prime", so we skip over it. + + ```text + 2 3 [4] 5 [6] 7 [8] [9] [10] + ↑ + ``` + - 7 is unmarked and is therefore a prime. + + ```text + 2 3 [4] 5 [6] 7 [8] [9] [10] + ↑ + ``` + - 8 is marked as "not prime", so we skip over it. + + ```text + 2 3 [4] 5 [6] 7 [8] [9] [10] + ↑ + ``` + - 9 is marked as "not prime", so we skip over it. + + ```text + 2 3 [4] 5 [6] 7 [8] [9] [10] + ↑ + ``` + - 10 is marked as "not prime", so we stop as there are no more numbers to check. -You've examined all numbers and found 2, 3, 5, and 7 are still unmarked, which means they're the primes less than or equal to 10. + ```text + 2 3 [4] 5 [6] 7 [8] [9] [10] + ↑ + ``` + +You've examined all the numbers and found that 2, 3, 5, and 7 are still unmarked, meaning they're the primes less than or equal to 10. diff --git a/exercises/practice/simple-cipher/.docs/instructions.md b/exercises/practice/simple-cipher/.docs/instructions.md index 475af618..33785744 100644 --- a/exercises/practice/simple-cipher/.docs/instructions.md +++ b/exercises/practice/simple-cipher/.docs/instructions.md @@ -11,14 +11,14 @@ If anyone wishes to decipher these, and get at their meaning, he must substitute 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. -The Caesar Cipher was used for some messages from Julius Caesar that were sent afield. +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. -Your task is to create a simple shift cipher like the Caesar Cipher. -This image is a great example of the Caesar Cipher: +Your task is to create a simple shift cipher like the Caesar cipher. +This image is a great example of the Caesar cipher: -![Caesar Cipher][img-caesar-cipher] +![Caesar cipher][img-caesar-cipher] For example: @@ -44,7 +44,7 @@ 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. +But if we set the key to "dddd", we would get the same thing as the Caesar cipher. ## Step 3 diff --git a/exercises/practice/square-root/.docs/instructions.md b/exercises/practice/square-root/.docs/instructions.md index e9905e9d..d258b868 100644 --- a/exercises/practice/square-root/.docs/instructions.md +++ b/exercises/practice/square-root/.docs/instructions.md @@ -1,13 +1,18 @@ # Instructions -Given a natural radicand, return its square root. +Your task is to calculate the square root of a given number. -Note that the term "radicand" refers to the number for which the root is to be determined. -That is, it is the number under the root symbol. +- Try to avoid using the pre-existing math libraries of your language. +- As input you'll be given a positive whole number, i.e. 1, 2, 3, 4… +- You are only required to handle cases where the result is a positive whole number. -Check out the Wikipedia pages on [square root][square-root] and [methods of computing square roots][computing-square-roots]. +Some potential approaches: -Recall also that natural numbers are positive real whole numbers (i.e. 1, 2, 3 and up). +- Linear or binary search for a number that gives the input number when squared. +- Successive approximation using Newton's or Heron's method. +- Calculating one digit at a time or one bit at a time. -[square-root]: https://en.wikipedia.org/wiki/Square_root +You can check out the Wikipedia pages on [integer square root][integer-square-root] and [methods of computing square roots][computing-square-roots] to help with choosing a method of calculation. + +[integer-square-root]: https://en.wikipedia.org/wiki/Integer_square_root [computing-square-roots]: https://en.wikipedia.org/wiki/Methods_of_computing_square_roots diff --git a/exercises/practice/square-root/.docs/introduction.md b/exercises/practice/square-root/.docs/introduction.md new file mode 100644 index 00000000..1d692934 --- /dev/null +++ b/exercises/practice/square-root/.docs/introduction.md @@ -0,0 +1,10 @@ +# Introduction + +We are launching a deep space exploration rocket and we need a way to make sure the navigation system stays on target. + +As the first step in our calculation, we take a target number and find its square root (that is, the number that when multiplied by itself equals the target number). + +The journey will be very long. +To make the batteries last as long as possible, we had to make our rocket's onboard computer very power efficient. +Unfortunately that means that we can't rely on fancy math libraries and functions, as they use more power. +Instead we want to implement our own square root calculation. diff --git a/exercises/practice/state-of-tic-tac-toe/.docs/instructions.md b/exercises/practice/state-of-tic-tac-toe/.docs/instructions.md index f525d358..1a03ebb6 100644 --- a/exercises/practice/state-of-tic-tac-toe/.docs/instructions.md +++ b/exercises/practice/state-of-tic-tac-toe/.docs/instructions.md @@ -3,7 +3,7 @@ In this exercise, you're going to implement a program that determines the state of a [tic-tac-toe][] game. (_You may also know the game as "noughts and crosses" or "Xs and Os"._) -The games is played on a 3×3 grid. +The game is played on a 3×3 grid. Players take turns to place `X`s and `O`s on the grid. The game ends when one player has won by placing three of marks in a row, column, or along a diagonal of the grid, or when the entire grid is filled up. diff --git a/exercises/practice/sublist/.docs/instructions.md b/exercises/practice/sublist/.docs/instructions.md index 7535931a..8228edc6 100644 --- a/exercises/practice/sublist/.docs/instructions.md +++ b/exercises/practice/sublist/.docs/instructions.md @@ -8,8 +8,8 @@ Given any two lists `A` and `B`, determine if: - None of the above is true, thus lists `A` and `B` are unequal Specifically, list `A` is equal to list `B` if both lists have the same values in the same order. -List `A` is a superlist of `B` if `A` contains a sub-sequence of values equal to `B`. -List `A` is a sublist of `B` if `B` contains a sub-sequence of values equal to `A`. +List `A` is a superlist of `B` if `A` contains a contiguous sub-sequence of values equal to `B`. +List `A` is a sublist of `B` if `B` contains a contiguous sub-sequence of values equal to `A`. Examples: