Linked Questions

522 votes
985 answers

"Hello, World!"

So... uh... this is a bit embarrassing. But we don't have a plain "Hello, World!" challenge yet (despite having 35 variants tagged with hello-world, and counting). While this is not the most ...
65 votes
115 answers

List of primes under a million

This is my first code golf question, and a very simple one at that, so I apologise in advance if I may have broken any community guidelines. The task is to print out, in ascending order, all of the ...
173 votes
495 answers

Implement a Truth-Machine

A truth-machine (credits goes to this guy for coming up with it) is a very simple program designed to demonstrate the I/O and control flow of a language. Here's what a truth-machine does: Gets a ...
145 votes
570 answers

Shortest infinite loop producing no output

Your task is to create the shortest infinite loop! The point of this challenge is to create an infinite loop producing no output, unlike its possible duplicate. The reason to this is because the code ...
27 votes
36 answers

Primes with prime bit-counts

Task Find all the non-negative integers up to and including a given non-zero positive integer n, that are prime and the count of 1's and ...
136 votes
11 answers

(-a) × (-a) = a × a

We all know that \$(-a) \times (-a) = a \times a\$ (hopefully), but can you prove it? Your task is to prove this fact using the ring axioms. What are the ring axioms? The ring axioms are a list of ...
43 votes
116 answers

Divisibility test

Task Given two strictly positive integers n and d as input, determine whether n is evenly divisible by d, i.e., if there exists an integer q such that n = qd. You ...
36 votes
41 answers

Is it a Mersenne Prime?

A number is a Mersenne Prime if it is both prime and can be written in the form 2n-1, where n is a positive integer. Your task is to, given any positive integer, determine whether or not it is a ...
196 votes
416 answers

1, 2, Fizz, 4, Buzz

Introduction In our recent effort to collect catalogues of shortest solutions for standard programming exercises, here is PPCG's first ever vanilla FizzBuzz challenge. If you wish to see other ...
244 votes
455 answers

Golf you a quine for great good!

Using your language of choice, golf a quine. A quine is a non-empty computer program which takes no input and produces a copy of its own source code as its only output. No cheating -- that means ...
35 votes
54 answers

Generating a random alphanumeric string of length N

What is the shortest way of generating a random string with a given length and with only alphanumeric characters allowed? example of a random string: with N = 9 output would be ...
106 votes
39 answers

Tips for golfing in Java

Are there any useful shortcuts that can be used in Java? As shown below, import already adds at least 17 characters to a program. ...
26 votes
31 answers

Magnanimous numbers

Given an positive integer as input determine if it is a magnanimous number. A magnanimous number is a number such that any insertion of a + sign between any two ...
17 votes
14 answers

I want 8 bits for every character!

This is the reverse of this challenge. Given an encoded list of codepoints and the characters used to encode it, you need to decompress it to its original string. For example, given the encoded list <...
13 votes
19 answers

Compute the minimum \$a(n)>a(n-1)\$ such that \$a(1)+a(2)+\dots+a(n)\$ is prime (OEIS A051935)

Background Consider the following sequence (A051935 in OEIS): Start with the term \$2\$. Find the lowest integer \$n\$ greater than \$2\$ such that \$2+n\$ is prime. Find the lowest integer \$n'\$ ...

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