Sync problem specs

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

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.

exercises/practice/grains/.meta/config.json

@@ -15,5 +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"
 }

exercises/practice/hamming/.docs/instructions.md

@@ -2,15 +2,6 @@
 
 Calculate the Hamming distance between two DNA strands.
 
-Your body is made up of cells that contain DNA.
-Those cells regularly wear out and need replacing, which they achieve by dividing into daughter cells.
-In fact, the average human body experiences about 10 quadrillion cell divisions in a lifetime!
-
-When cells divide, their DNA replicates too.
-Sometimes during this process mistakes happen and single pieces of DNA get encoded with the incorrect information.
-If we compare two strands of DNA and count the differences between them we can see how many mistakes occurred.
-This is known as the "Hamming distance".
-
 We read DNA using the letters C, A, G and T.
 Two strands might look like this:
 
@@ -20,8 +11,6 @@ Two strands might look like this:
 
 They have 7 differences, and therefore the Hamming distance is 7.
 
-The Hamming distance is useful for lots of things in science, not just biology, so it's a nice phrase to be familiar with :)
-
 ## Implementation notes
 
 The Hamming distance is only defined for sequences of equal length, so an attempt to calculate it between sequences of different lengths should not work.

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 :)

exercises/practice/hamming/.meta/config.json

@@ -14,7 +14,7 @@
       ".meta/Example.bat"
     ]
   },
-  "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/"
 }

exercises/practice/leap/.meta/config.json

@@ -15,5 +15,5 @@
   },
   "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"
 }

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.

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

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.