diff --git a/exercises/practice/acronym/.docs/instructions.md b/exercises/practice/acronym/.docs/instructions.md index c62fc3e85..133bd2cbb 100644 --- a/exercises/practice/acronym/.docs/instructions.md +++ b/exercises/practice/acronym/.docs/instructions.md @@ -10,8 +10,8 @@ Punctuation is handled as follows: hyphens are word separators (like whitespace) For example: -|Input|Output| -|-|-| -|As Soon As Possible|ASAP| -|Liquid-crystal display|LCD| -|Thank George It's Friday!|TGIF| +| Input | Output | +| ------------------------- | ------ | +| As Soon As Possible | ASAP | +| Liquid-crystal display | LCD | +| Thank George It's Friday! | TGIF | diff --git a/exercises/practice/allergies/.docs/instructions.md b/exercises/practice/allergies/.docs/instructions.md index a13949209..daf8cfde2 100644 --- a/exercises/practice/allergies/.docs/instructions.md +++ b/exercises/practice/allergies/.docs/instructions.md @@ -22,6 +22,6 @@ Now, given just that score of 34, your program should be able to say: - Whether Tom is allergic to any one of those allergens listed above. - All the allergens Tom is allergic to. -Note: a given score may include allergens **not** listed above (i.e. allergens that score 256, 512, 1024, etc.). +Note: a given score may include allergens **not** listed above (i.e. allergens that score 256, 512, 1024, etc.). Your program should ignore those components of the score. For example, if the allergy score is 257, your program should only report the eggs (1) allergy. diff --git a/exercises/practice/armstrong-numbers/.docs/instructions.md b/exercises/practice/armstrong-numbers/.docs/instructions.md index 744cfbe7f..5e56bbe46 100644 --- a/exercises/practice/armstrong-numbers/.docs/instructions.md +++ b/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. diff --git a/exercises/practice/atbash-cipher/.docs/instructions.md b/exercises/practice/atbash-cipher/.docs/instructions.md index 21ca2ce0a..1e7627b1e 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 c858dc336..df79bbc5e 100644 --- a/exercises/practice/atbash-cipher/.meta/config.json +++ b/exercises/practice/atbash-cipher/.meta/config.json @@ -25,7 +25,7 @@ ".meta/example.h" ] }, - "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/binary-search-tree/.meta/config.json b/exercises/practice/binary-search-tree/.meta/config.json index 8e2edff96..a74adaa8e 100644 --- a/exercises/practice/binary-search-tree/.meta/config.json +++ b/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" } diff --git a/exercises/practice/binary-search/.docs/instructions.md b/exercises/practice/binary-search/.docs/instructions.md index aa1946cfb..12f4358eb 100644 --- a/exercises/practice/binary-search/.docs/instructions.md +++ b/exercises/practice/binary-search/.docs/instructions.md @@ -11,7 +11,7 @@ Binary search only works when a list has been sorted. The algorithm looks like this: -- Find the middle element of a *sorted* list and compare it with the item we're looking for. +- Find the middle element of a _sorted_ list and compare it with the item we're looking for. - If the middle element is our item, then we're done! - If the middle element is greater than our item, we can eliminate that element and all the elements **after** it. - If the middle element is less than our item, we can eliminate that element and all the elements **before** it. diff --git a/exercises/practice/binary/.docs/instructions.md b/exercises/practice/binary/.docs/instructions.md index 046fd3e09..6722637eb 100644 --- a/exercises/practice/binary/.docs/instructions.md +++ b/exercises/practice/binary/.docs/instructions.md @@ -20,7 +20,7 @@ A number 23 in base 10 notation can be understood as a linear combination of pow - 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` diff --git a/exercises/practice/circular-buffer/.docs/instructions.md b/exercises/practice/circular-buffer/.docs/instructions.md index 3487a0f61..2ba1fda2a 100644 --- a/exercises/practice/circular-buffer/.docs/instructions.md +++ b/exercises/practice/circular-buffer/.docs/instructions.md @@ -4,39 +4,55 @@ A circular buffer, cyclic buffer or ring buffer is a data structure that uses a A circular buffer first starts empty and of some predefined length. For example, this is a 7-element buffer: - - [ ][ ][ ][ ][ ][ ][ ] + +```text +[ ][ ][ ][ ][ ][ ][ ] +``` Assume that a 1 is written into the middle of the buffer (exact starting location does not matter in a circular buffer): - - [ ][ ][ ][1][ ][ ][ ] + +```text +[ ][ ][ ][1][ ][ ][ ] +``` Then assume that two more elements are added — 2 & 3 — which get appended after the 1: - - [ ][ ][ ][1][2][3][ ] + +```text +[ ][ ][ ][1][2][3][ ] +``` If two elements are then removed from the buffer, the oldest values inside the buffer are removed. The two elements removed, in this case, are 1 & 2, leaving the buffer with just a 3: - - [ ][ ][ ][ ][ ][3][ ] + +```text +[ ][ ][ ][ ][ ][3][ ] +``` If the buffer has 7 elements then it is completely full: - - [5][6][7][8][9][3][4] + +```text +[5][6][7][8][9][3][4] +``` When the buffer is full an error will be raised, alerting the client that further writes are blocked until a slot becomes free. When the buffer is full, the client can opt to overwrite the oldest data with a forced write. In this case, two more elements — A & B — are added and they overwrite the 3 & 4: - - [5][6][7][8][9][A][B] + +```text +[5][6][7][8][9][A][B] +``` 3 & 4 have been replaced by A & B making 5 now the oldest data in the buffer. Finally, if two elements are removed then what would be returned is 5 & 6 yielding the buffer: - - [ ][ ][7][8][9][A][B] + +```text +[ ][ ][7][8][9][A][B] +``` Because there is space available, if the client again uses overwrite to store C & D then the space where 5 & 6 were stored previously will be used not the location of 7 & 8. 7 is still the oldest element and the buffer is once again full. - - [C][D][7][8][9][A][B] + +```text +[C][D][7][8][9][A][B] +``` diff --git a/exercises/practice/clock/.meta/config.json b/exercises/practice/clock/.meta/config.json index 601b4acc2..70dca9fd8 100644 --- a/exercises/practice/clock/.meta/config.json +++ b/exercises/practice/clock/.meta/config.json @@ -25,6 +25,5 @@ ] }, "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" } diff --git a/exercises/practice/complex-numbers/.docs/instructions.md b/exercises/practice/complex-numbers/.docs/instructions.md index 50b19aedf..2b8a7a49d 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/darts/.docs/instructions.md b/exercises/practice/darts/.docs/instructions.md index 70f0e53da..6518201c7 100644 --- a/exercises/practice/darts/.docs/instructions.md +++ b/exercises/practice/darts/.docs/instructions.md @@ -1,11 +1,13 @@ # Instructions -Write a function that returns the earned points in a single toss of a Darts game. +Calculate the points scored in a single toss of a Darts game. [Darts][darts] is a game where players throw darts at a [target][darts-target]. In our particular instance of the game, the target rewards 4 different amounts of points, depending on where the dart lands: +![Our dart scoreboard with values from a complete miss to a bullseye](https://assets.exercism.org/images/exercises/darts/darts-scoreboard.svg) + - If the dart lands outside the target, player earns no points (0 points). - If the dart lands in the outer circle of the target, player earns 1 point. - If the dart lands in the middle circle of the target, player earns 5 points. @@ -14,10 +16,16 @@ In our particular instance of the game, the target rewards 4 different amounts o The outer circle has a radius of 10 units (this is equivalent to the total radius for the entire target), the middle circle a radius of 5 units, and the inner circle a radius of 1. Of course, they are all centered at the same point — that is, the circles are [concentric][] defined by the coordinates (0, 0). -Write a function that given a point in the target (defined by its [Cartesian coordinates][cartesian-coordinates] `x` and `y`, where `x` and `y` are [real][real-numbers]), returns the correct amount earned by a dart landing at that point. +Given a point in the target (defined by its [Cartesian coordinates][cartesian-coordinates] `x` and `y`, where `x` and `y` are [real][real-numbers]), calculate the correct score earned by a dart landing at that point. + +## Credit + +The scoreboard image was created by [habere-et-dispertire][habere-et-dispertire] using [Inkscape][inkscape]. [darts]: https://en.wikipedia.org/wiki/Darts [darts-target]: https://en.wikipedia.org/wiki/Darts#/media/File:Darts_in_a_dartboard.jpg [concentric]: https://mathworld.wolfram.com/ConcentricCircles.html [cartesian-coordinates]: https://www.mathsisfun.com/data/cartesian-coordinates.html [real-numbers]: https://www.mathsisfun.com/numbers/real-numbers.html +[habere-et-dispertire]: https://exercism.org/profiles/habere-et-dispertire +[inkscape]: https://en.wikipedia.org/wiki/Inkscape diff --git a/exercises/practice/darts/.meta/config.json b/exercises/practice/darts/.meta/config.json index 022fd8790..e7baba481 100644 --- a/exercises/practice/darts/.meta/config.json +++ b/exercises/practice/darts/.meta/config.json @@ -18,6 +18,6 @@ ".meta/example.h" ] }, - "blurb": "Write a function that returns the earned points in a single toss of a Darts game.", + "blurb": "Calculate the points scored in a single toss of a Darts game.", "source": "Inspired by an exercise created by a professor Della Paolera in Argentina" } diff --git a/exercises/practice/eliuds-eggs/.docs/introduction.md b/exercises/practice/eliuds-eggs/.docs/introduction.md index 49eaffd8b..819897480 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/grade-school/.docs/instructions.md b/exercises/practice/grade-school/.docs/instructions.md index 9a63e398d..3cb1b5d5f 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/hamming/.docs/instructions.md b/exercises/practice/hamming/.docs/instructions.md index 020fdd02d..8f47a179e 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 000000000..8419bf479 --- /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 283d2e941..602f1cfd3 100644 --- a/exercises/practice/hamming/.meta/config.json +++ b/exercises/practice/hamming/.meta/config.json @@ -32,7 +32,7 @@ ".meta/example.h" ] }, - "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/hello-world/.meta/config.json b/exercises/practice/hello-world/.meta/config.json index d93a0d3be..0446fddce 100644 --- a/exercises/practice/hello-world/.meta/config.json +++ b/exercises/practice/hello-world/.meta/config.json @@ -27,7 +27,7 @@ ".meta/example.c" ] }, - "blurb": "The classical introductory exercise. Just say \"Hello, World!\".", + "blurb": "Exercism's classic introductory exercise. Just say \"Hello, World!\".", "source": "This is an exercise to introduce users to using Exercism", "source_url": "https://en.wikipedia.org/wiki/%22Hello,_world!%22_program" } diff --git a/exercises/practice/isogram/.docs/instructions.md b/exercises/practice/isogram/.docs/instructions.md index 5e4884476..2e8df851a 100644 --- a/exercises/practice/isogram/.docs/instructions.md +++ b/exercises/practice/isogram/.docs/instructions.md @@ -11,4 +11,4 @@ Examples of isograms: - downstream - six-year-old -The word *isograms*, however, is not an isogram, because the s repeats. +The word _isograms_, however, is not an isogram, because the s repeats. diff --git a/exercises/practice/knapsack/.docs/instructions.md b/exercises/practice/knapsack/.docs/instructions.md index 3411db988..0ebf7914c 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 9b2bed8b4..9ac9df596 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/list-ops/.docs/instructions.md b/exercises/practice/list-ops/.docs/instructions.md index ccfc2f8b2..ebc5dffed 100644 --- a/exercises/practice/list-ops/.docs/instructions.md +++ b/exercises/practice/list-ops/.docs/instructions.md @@ -7,13 +7,13 @@ Implement a series of basic list operations, without using existing functions. The precise number and names of the operations to be implemented will be track dependent to avoid conflicts with existing names, but the general operations you will implement include: -- `append` (*given two lists, add all items in the second list to the end of the first list*); -- `concatenate` (*given a series of lists, combine all items in all lists into one flattened list*); -- `filter` (*given a predicate and a list, return the list of all items for which `predicate(item)` is True*); -- `length` (*given a list, return the total number of items within it*); -- `map` (*given a function and a list, return the list of the results of applying `function(item)` on all items*); -- `foldl` (*given a function, a list, and initial accumulator, fold (reduce) each item into the accumulator from the left*); -- `foldr` (*given a function, a list, and an initial accumulator, fold (reduce) each item into the accumulator from the right*); -- `reverse` (*given a list, return a list with all the original items, but in reversed order*). +- `append` (_given two lists, add all items in the second list to the end of the first list_); +- `concatenate` (_given a series of lists, combine all items in all lists into one flattened list_); +- `filter` (_given a predicate and a list, return the list of all items for which `predicate(item)` is True_); +- `length` (_given a list, return the total number of items within it_); +- `map` (_given a function and a list, return the list of the results of applying `function(item)` on all items_); +- `foldl` (_given a function, a list, and initial accumulator, fold (reduce) each item into the accumulator from the left_); +- `foldr` (_given a function, a list, and an initial accumulator, fold (reduce) each item into the accumulator from the right_); +- `reverse` (_given a list, return a list with all the original items, but in reversed order_). Note, the ordering in which arguments are passed to the fold functions (`foldl`, `foldr`) is significant. diff --git a/exercises/practice/luhn/.docs/instructions.md b/exercises/practice/luhn/.docs/instructions.md index 8cbe791fc..49934c106 100644 --- a/exercises/practice/luhn/.docs/instructions.md +++ b/exercises/practice/luhn/.docs/instructions.md @@ -22,7 +22,8 @@ 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/matching-brackets/.docs/instructions.md b/exercises/practice/matching-brackets/.docs/instructions.md index 544daa968..ea1708423 100644 --- a/exercises/practice/matching-brackets/.docs/instructions.md +++ b/exercises/practice/matching-brackets/.docs/instructions.md @@ -1,4 +1,5 @@ # Instructions Given a string containing brackets `[]`, braces `{}`, parentheses `()`, or any combination thereof, verify that any and all pairs are matched and nested correctly. -The string may also contain other characters, which for the purposes of this exercise should be ignored. +Any other characters should be ignored. +For example, `"{what is (42)}?"` is balanced and `"[text}"` is not. diff --git a/exercises/practice/matching-brackets/.docs/introduction.md b/exercises/practice/matching-brackets/.docs/introduction.md new file mode 100644 index 000000000..0618221b2 --- /dev/null +++ b/exercises/practice/matching-brackets/.docs/introduction.md @@ -0,0 +1,8 @@ +# Introduction + +You're given the opportunity to write software for the Bracketeer™, an ancient but powerful mainframe. +The software that runs on it is written in a proprietary language. +Much of its syntax is familiar, but you notice _lots_ of brackets, braces and parentheses. +Despite the Bracketeer™ being powerful, it lacks flexibility. +If the source code has any unbalanced brackets, braces or parentheses, the Bracketeer™ crashes and must be rebooted. +To avoid such a scenario, you start writing code that can verify that brackets, braces, and parentheses are balanced before attempting to run it on the Bracketeer™. diff --git a/exercises/practice/pascals-triangle/.docs/instructions.md b/exercises/practice/pascals-triangle/.docs/instructions.md index f55678593..0f58f0069 100644 --- a/exercises/practice/pascals-triangle/.docs/instructions.md +++ b/exercises/practice/pascals-triangle/.docs/instructions.md @@ -1,8 +1,20 @@ # Instructions -Compute Pascal's triangle up to a given number of rows. +Your task is to output the first N rows of Pascal's triangle. -In Pascal's Triangle each number is computed by adding the numbers to the right and left of the current position in the previous row. +[Pascal's triangle][wikipedia] is a triangular array of positive integers. + +In Pascal's triangle, the number of values in a row is equal to its row number (which starts at one). +Therefore, the first row has one value, the second row has two values, and so on. + +The first (topmost) row has a single value: `1`. +Subsequent rows' values are computed by adding the numbers directly to the right and left of the current position in the previous row. + +If the previous row does _not_ have a value to the left or right of the current position (which only happens for the leftmost and rightmost positions), treat that position's value as zero (effectively "ignoring" it in the summation). + +## Example + +Let's look at the first 5 rows of Pascal's Triangle: ```text 1 @@ -10,5 +22,14 @@ In Pascal's Triangle each number is computed by adding the numbers to the right 1 2 1 1 3 3 1 1 4 6 4 1 -# ... etc ``` + +The topmost row has one value, which is `1`. + +The leftmost and rightmost values have only one preceding position to consider, which is the position to its right respectively to its left. +With the topmost value being `1`, it follows from this that all the leftmost and rightmost values are also `1`. + +The other values all have two positions to consider. +For example, the fifth row's (`1 4 6 4 1`) middle value is `6`, as the values to its left and right in the preceding row are `3` and `3`: + +[wikipedia]: https://en.wikipedia.org/wiki/Pascal%27s_triangle diff --git a/exercises/practice/pascals-triangle/.docs/introduction.md b/exercises/practice/pascals-triangle/.docs/introduction.md new file mode 100644 index 000000000..60b8ec30d --- /dev/null +++ b/exercises/practice/pascals-triangle/.docs/introduction.md @@ -0,0 +1,22 @@ +# Introduction + +With the weather being great, you're not looking forward to spending an hour in a classroom. +Annoyed, you enter the class room, where you notice a strangely satisfying triangle shape on the blackboard. +Whilst waiting for your math teacher to arrive, you can't help but notice some patterns in the triangle: the outer values are all ones, each subsequent row has one more value than its previous row and the triangle is symmetrical. +Weird! + +Not long after you sit down, your teacher enters the room and explains that this triangle is the famous [Pascal's triangle][wikipedia]. + +Over the next hour, your teacher reveals some amazing things hidden in this triangle: + +- It can be used to compute how many ways you can pick K elements from N values. +- 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! +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. + +[wikipedia]: https://en.wikipedia.org/wiki/Pascal%27s_triangle +[wikipedia-sierpinski-triangle]: https://en.wikipedia.org/wiki/Sierpi%C5%84ski_triangle diff --git a/exercises/practice/perfect-numbers/.docs/instructions.md b/exercises/practice/perfect-numbers/.docs/instructions.md index 0dae8867f..b2bc82ca3 100644 --- a/exercises/practice/perfect-numbers/.docs/instructions.md +++ b/exercises/practice/perfect-numbers/.docs/instructions.md @@ -1,24 +1,39 @@ # Instructions -Determine if a number is perfect, abundant, or deficient based on -Nicomachus' (60 - 120 CE) classification scheme for positive integers. - -The Greek mathematician [Nicomachus][nicomachus] devised a classification scheme for positive integers, identifying each as belonging uniquely to the categories of **perfect**, **abundant**, or **deficient** based on their [aliquot sum][aliquot-sum]. -The aliquot sum is defined as the sum of the factors of a number not including the number itself. -For example, the aliquot sum of 15 is (1 + 3 + 5) = 9 - -- **Perfect**: aliquot sum = number - - 6 is a perfect number because (1 + 2 + 3) = 6 - - 28 is a perfect number because (1 + 2 + 4 + 7 + 14) = 28 -- **Abundant**: aliquot sum > number - - 12 is an abundant number because (1 + 2 + 3 + 4 + 6) = 16 - - 24 is an abundant number because (1 + 2 + 3 + 4 + 6 + 8 + 12) = 36 -- **Deficient**: aliquot sum < number - - 8 is a deficient number because (1 + 2 + 4) = 7 - - Prime numbers are deficient - -Implement a way to determine whether a given number is **perfect**. -Depending on your language track, you may also need to implement a way to determine whether a given number is **abundant** or **deficient**. +Determine if a number is perfect, abundant, or deficient based on Nicomachus' (60 - 120 CE) classification scheme for positive integers. + +The Greek mathematician [Nicomachus][nicomachus] devised a classification scheme for positive integers, identifying each as belonging uniquely to the categories of [perfect](#perfect), [abundant](#abundant), or [deficient](#deficient) based on their [aliquot sum][aliquot-sum]. +The _aliquot sum_ is defined as the sum of the factors of a number not including the number itself. +For example, the aliquot sum of `15` is `1 + 3 + 5 = 9`. + +## Perfect + +A number is perfect when it equals its aliquot sum. +For example: + +- `6` is a perfect number because `1 + 2 + 3 = 6` +- `28` is a perfect number because `1 + 2 + 4 + 7 + 14 = 28` + +## Abundant + +A number is abundant when it is less than its aliquot sum. +For example: + +- `12` is an abundant number because `1 + 2 + 3 + 4 + 6 = 16` +- `24` is an abundant number because `1 + 2 + 3 + 4 + 6 + 8 + 12 = 36` + +## Deficient + +A number is deficient when it is greater than its aliquot sum. +For example: + +- `8` is a deficient number because `1 + 2 + 4 = 7` +- Prime numbers are deficient + +## Task + +Implement a way to determine whether a given number is [perfect](#perfect). +Depending on your language track, you may also need to implement a way to determine whether a given number is [abundant](#abundant) or [deficient](#deficient). [nicomachus]: https://en.wikipedia.org/wiki/Nicomachus [aliquot-sum]: https://en.wikipedia.org/wiki/Aliquot_sum diff --git a/exercises/practice/phone-number/.docs/instructions.md b/exercises/practice/phone-number/.docs/instructions.md index 6d3275cdf..62ba48e96 100644 --- a/exercises/practice/phone-number/.docs/instructions.md +++ b/exercises/practice/phone-number/.docs/instructions.md @@ -5,18 +5,20 @@ Clean up user-entered phone numbers so that they can be sent SMS messages. The **North American Numbering Plan (NANP)** is a telephone numbering system used by many countries in North America like the United States, Canada or Bermuda. All NANP-countries share the same international country code: `1`. -NANP numbers are ten-digit numbers consisting of a three-digit Numbering Plan Area code, commonly known as *area code*, followed by a seven-digit local number. -The first three digits of the local number represent the *exchange code*, followed by the unique four-digit number which is the *subscriber number*. +NANP numbers are ten-digit numbers consisting of a three-digit Numbering Plan Area code, commonly known as _area code_, followed by a seven-digit local number. +The first three digits of the local number represent the _exchange code_, followed by the unique four-digit number which is the _subscriber number_. The format is usually represented as ```text -(NXX)-NXX-XXXX +NXX NXX-XXXX ``` where `N` is any digit from 2 through 9 and `X` is any digit from 0 through 9. -Your task is to clean up differently formatted telephone numbers by removing punctuation and the country code (1) if present. +Sometimes they also have the country code (represented as `1` or `+1`) prefixed. + +Your task is to clean up differently formatted telephone numbers by removing punctuation and the country code if present. For example, the inputs diff --git a/exercises/practice/pig-latin/.docs/instructions.md b/exercises/practice/pig-latin/.docs/instructions.md index 6c843080d..a9645ac23 100644 --- a/exercises/practice/pig-latin/.docs/instructions.md +++ b/exercises/practice/pig-latin/.docs/instructions.md @@ -19,7 +19,7 @@ For example: ## Rule 2 -If a word begins with a one or more consonants, first move those consonants to the end of the word and then add an `"ay"` sound to the end of the word. +If a word begins with one or more consonants, first move those consonants to the end of the word and then add an `"ay"` sound to the end of the word. For example: @@ -33,7 +33,7 @@ If a word starts with zero or more consonants followed by `"qu"`, first move tho For example: -- `"quick"` -> `"ickqu"` -> `"ay"` (starts with `"qu"`, no preceding consonants) +- `"quick"` -> `"ickqu"` -> `"ickquay"` (starts with `"qu"`, no preceding consonants) - `"square"` -> `"aresqu"` -> `"aresquay"` (starts with one consonant followed by `"qu`") ## Rule 4 diff --git a/exercises/practice/protein-translation/.docs/instructions.md b/exercises/practice/protein-translation/.docs/instructions.md index 7dc34d2ed..44880802c 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 1c1a8aea6..ced833d7a 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 000000000..3453c6ed4 --- /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 7f64bd295..8a44ea2c6 100644 --- a/exercises/practice/pythagorean-triplet/.meta/config.json +++ b/exercises/practice/pythagorean-triplet/.meta/config.json @@ -18,7 +18,7 @@ ".meta/example.h" ] }, - "blurb": "There exists exactly one Pythagorean triplet for which a + b + c = 1000. Find the product a * b * c.", - "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/queen-attack/.docs/instructions.md b/exercises/practice/queen-attack/.docs/instructions.md index ad7ea9547..97f22a0ae 100644 --- a/exercises/practice/queen-attack/.docs/instructions.md +++ b/exercises/practice/queen-attack/.docs/instructions.md @@ -8,18 +8,14 @@ A chessboard can be represented by an 8 by 8 array. So if you are told the white queen is at `c5` (zero-indexed at column 2, row 3) and the black queen at `f2` (zero-indexed at column 5, row 6), then you know that the set-up is like so: -```text - a b c d e f g h -8 _ _ _ _ _ _ _ _ 8 -7 _ _ _ _ _ _ _ _ 7 -6 _ _ _ _ _ _ _ _ 6 -5 _ _ W _ _ _ _ _ 5 -4 _ _ _ _ _ _ _ _ 4 -3 _ _ _ _ _ _ _ _ 3 -2 _ _ _ _ _ B _ _ 2 -1 _ _ _ _ _ _ _ _ 1 - a b c d e f g h -``` +![A chess board with two queens. Arrows emanating from the queen at c5 indicate possible directions of capture along file, rank and diagonal.](https://assets.exercism.org/images/exercises/queen-attack/queen-capture.svg) You are also able to answer whether the queens can attack each other. In this case, that answer would be yes, they can, because both pieces share a diagonal. + +## Credit + +The chessboard image was made by [habere-et-dispertire][habere-et-dispertire] using LaTeX and the [chessboard package][chessboard-package] by Ulrike Fischer. + +[habere-et-dispertire]: https://exercism.org/profiles/habere-et-dispertire +[chessboard-package]: https://github.com/u-fischer/chessboard diff --git a/exercises/practice/raindrops/.meta/config.json b/exercises/practice/raindrops/.meta/config.json index 3ff0ea854..3d5b0a910 100644 --- a/exercises/practice/raindrops/.meta/config.json +++ b/exercises/practice/raindrops/.meta/config.json @@ -32,7 +32,7 @@ ".meta/example.h" ] }, - "blurb": "Convert a number to a string, the content of which depends on the number's factors.", + "blurb": "Convert a number into its corresponding raindrop sounds - Pling, Plang and Plong.", "source": "A variation on FizzBuzz, a famous technical interview question that is intended to weed out potential candidates. That question is itself derived from Fizz Buzz, a popular children's game for teaching division.", "source_url": "https://en.wikipedia.org/wiki/Fizz_buzz" } diff --git a/exercises/practice/rna-transcription/.docs/instructions.md b/exercises/practice/rna-transcription/.docs/instructions.md index 36da381f5..4dbfd3a27 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/say/.docs/instructions.md b/exercises/practice/say/.docs/instructions.md index fb4a6dfb9..ad3d34778 100644 --- a/exercises/practice/say/.docs/instructions.md +++ b/exercises/practice/say/.docs/instructions.md @@ -30,8 +30,6 @@ Implement breaking a number up into chunks of thousands. So `1234567890` should yield a list like 1, 234, 567, and 890, while the far simpler `1000` should yield just 1 and 0. -The program must also report any values that are out of range. - ## Step 3 Now handle inserting the appropriate scale word between those chunks. diff --git a/exercises/practice/series/.docs/instructions.md b/exercises/practice/series/.docs/instructions.md index e32cc38c6..fd97a6706 100644 --- a/exercises/practice/series/.docs/instructions.md +++ b/exercises/practice/series/.docs/instructions.md @@ -15,5 +15,5 @@ And the following 4-digit series: And if you ask for a 6-digit series from a 5-digit string, you deserve whatever you get. -Note that these series are only required to occupy *adjacent positions* in the input; -the digits need not be *numerically consecutive*. +Note that these series are only required to occupy _adjacent positions_ in the input; +the digits need not be _numerically consecutive_. diff --git a/exercises/practice/space-age/.docs/instructions.md b/exercises/practice/space-age/.docs/instructions.md index fe938cc09..f23b5e2c1 100644 --- a/exercises/practice/space-age/.docs/instructions.md +++ b/exercises/practice/space-age/.docs/instructions.md @@ -1,25 +1,28 @@ # Instructions -Given an age in seconds, calculate how old someone would be on: +Given an age in seconds, calculate how old someone would be on a planet in our Solar System. -- Mercury: orbital period 0.2408467 Earth years -- Venus: orbital period 0.61519726 Earth years -- Earth: orbital period 1.0 Earth years, 365.25 Earth days, or 31557600 seconds -- Mars: orbital period 1.8808158 Earth years -- Jupiter: orbital period 11.862615 Earth years -- Saturn: orbital period 29.447498 Earth years -- Uranus: orbital period 84.016846 Earth years -- Neptune: orbital period 164.79132 Earth years +One Earth year equals 365.25 Earth days, or 31,557,600 seconds. +If you were told someone was 1,000,000,000 seconds old, their age would be 31.69 Earth-years. -So if you were told someone were 1,000,000,000 seconds old, you should -be able to say that they're 31.69 Earth-years old. +For the other planets, you have to account for their orbital period in Earth Years: -If you're wondering why Pluto didn't make the cut, go watch [this YouTube video][pluto-video]. +| Planet | Orbital period in Earth Years | +| ------- | ----------------------------- | +| Mercury | 0.2408467 | +| Venus | 0.61519726 | +| Earth | 1.0 | +| Mars | 1.8808158 | +| Jupiter | 11.862615 | +| Saturn | 29.447498 | +| Uranus | 84.016846 | +| Neptune | 164.79132 | -Note: The actual length of one complete orbit of the Earth around the sun is closer to 365.256 days (1 sidereal year). +~~~~exercism/note +The actual length of one complete orbit of the Earth around the sun is closer to 365.256 days (1 sidereal year). The Gregorian calendar has, on average, 365.2425 days. While not entirely accurate, 365.25 is the value used in this exercise. See [Year on Wikipedia][year] for more ways to measure a year. -[pluto-video]: https://www.youtube.com/watch?v=Z_2gbGXzFbs [year]: https://en.wikipedia.org/wiki/Year#Summary +~~~~ diff --git a/exercises/practice/space-age/.docs/introduction.md b/exercises/practice/space-age/.docs/introduction.md new file mode 100644 index 000000000..014d78857 --- /dev/null +++ b/exercises/practice/space-age/.docs/introduction.md @@ -0,0 +1,20 @@ +# Introduction + +The year is 2525 and you've just embarked on a journey to visit all planets in the Solar System (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune). +The first stop is Mercury, where customs require you to fill out a form (bureaucracy is apparently _not_ Earth-specific). +As you hand over the form to the customs officer, they scrutinize it and frown. +"Do you _really_ expect me to believe you're just 50 years old? +You must be closer to 200 years old!" + +Amused, you wait for the customs officer to start laughing, but they appear to be dead serious. +You realize that you've entered your age in _Earth years_, but the officer expected it in _Mercury years_! +As Mercury's orbital period around the sun is significantly shorter than Earth, you're actually a lot older in Mercury years. +After some quick calculations, you're able to provide your age in Mercury Years. +The customs officer smiles, satisfied, and waves you through. +You make a mental note to pre-calculate your planet-specific age _before_ future customs checks, to avoid such mix-ups. + +~~~~exercism/note +If you're wondering why Pluto didn't make the cut, go watch [this YouTube video][pluto-video]. + +[pluto-video]: https://www.youtube.com/watch?v=Z_2gbGXzFbs +~~~~ diff --git a/exercises/practice/square-root/.docs/instructions.md b/exercises/practice/square-root/.docs/instructions.md index e9905e9d4..d258b8687 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 000000000..1d692934f --- /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/sublist/.docs/instructions.md b/exercises/practice/sublist/.docs/instructions.md index 7535931af..8228edc6c 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: diff --git a/exercises/practice/two-bucket/.docs/instructions.md b/exercises/practice/two-bucket/.docs/instructions.md index 7249deb36..30d779aa9 100644 --- a/exercises/practice/two-bucket/.docs/instructions.md +++ b/exercises/practice/two-bucket/.docs/instructions.md @@ -11,7 +11,7 @@ There are some rules that your solution must follow: b) the second bucket is full 2. Emptying a bucket and doing nothing to the other. 3. Filling a bucket and doing nothing to the other. -- After an action, you may not arrive at a state where the starting bucket is empty and the other bucket is full. +- After an action, you may not arrive at a state where the initial starting bucket is empty and the other bucket is full. Your program will take as input: diff --git a/exercises/practice/wordy/.docs/instructions.md b/exercises/practice/wordy/.docs/instructions.md index 0b9e67b6c..aafb9ee54 100644 --- a/exercises/practice/wordy/.docs/instructions.md +++ b/exercises/practice/wordy/.docs/instructions.md @@ -48,7 +48,7 @@ Since these are verbal word problems, evaluate the expression from left-to-right > What is 3 plus 2 multiplied by 3? -15 (i.e. not 9) +15 (i.e. not 9) ## Iteration 4 — Errors diff --git a/exercises/practice/yacht/.meta/config.json b/exercises/practice/yacht/.meta/config.json index dcfd2a7c7..aa50ce0b7 100644 --- a/exercises/practice/yacht/.meta/config.json +++ b/exercises/practice/yacht/.meta/config.json @@ -16,6 +16,6 @@ ] }, "blurb": "Score a single throw of dice in the game Yacht.", - "source": "James Kilfiger, using wikipedia", + "source": "James Kilfiger, using Wikipedia", "source_url": "https://en.wikipedia.org/wiki/Yacht_(dice_game)" } diff --git a/exercises/practice/zebra-puzzle/.docs/instructions.md b/exercises/practice/zebra-puzzle/.docs/instructions.md index c666e33cb..aedce9b25 100644 --- a/exercises/practice/zebra-puzzle/.docs/instructions.md +++ b/exercises/practice/zebra-puzzle/.docs/instructions.md @@ -12,20 +12,20 @@ The following 15 statements are all known to be true: 1. There are five houses. 2. The Englishman lives in the red house. 3. The Spaniard owns the dog. -4. Coffee is drunk in the green house. +4. The person in the green house drinks coffee. 5. The Ukrainian drinks tea. 6. The green house is immediately to the right of the ivory house. -7. The Old Gold smoker owns snails. -8. Kools are smoked in the yellow house. -9. Milk is drunk in the middle house. +7. The snail owner likes to go dancing. +8. The person in the yellow house is a painter. +9. The person in the middle house drinks milk. 10. The Norwegian lives in the first house. -11. The man who smokes Chesterfields lives in the house next to the man with the fox. -12. Kools are smoked in the house next to the house where the horse is kept. -13. The Lucky Strike smoker drinks orange juice. -14. The Japanese smokes Parliaments. +11. The person who enjoys reading lives in the house next to the person with the fox. +12. The painter's house is next to the house with the horse. +13. The person who plays football drinks orange juice. +14. The Japanese person plays chess. 15. The Norwegian lives next to the blue house. -Additionally, each of the five houses is painted a different color, and their inhabitants are of different national extractions, own different pets, drink different beverages and smoke different brands of cigarettes. +Additionally, each of the five houses is painted a different color, and their inhabitants are of different national extractions, own different pets, drink different beverages and engage in different hobbies. ~~~~exercism/note There are 24 billion (5!⁵ = 24,883,200,000) possible solutions, so try ruling out as many solutions as possible. diff --git a/exercises/practice/zebra-puzzle/.docs/introduction.md b/exercises/practice/zebra-puzzle/.docs/introduction.md index 33d688fd5..bbcaa6fd2 100644 --- a/exercises/practice/zebra-puzzle/.docs/introduction.md +++ b/exercises/practice/zebra-puzzle/.docs/introduction.md @@ -1,7 +1,7 @@ # Introduction The Zebra Puzzle is a famous logic puzzle in which there are five houses, each painted a different color. -The houses have different inhabitants, who have different nationalities, own different pets, drink different beverages and smoke different brands of cigarettes. +The houses have different inhabitants, who have different nationalities, own different pets, drink different beverages and enjoy different hobbies. To help you solve the puzzle, you're given 15 statements describing the solution. However, only by combining the information in _all_ statements will you be able to find the solution to the puzzle.