A code challenge is a competition for creative ways to solve a programming puzzle with an objective winning criterion not covered by other scoring tags (e.g. code-golf).

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17
votes
6answers
2k views

Take It or Leave It II: A Game Show for Computers

This is the second in a series of puzzles that I will be posting every Monday at Midnight PST. The first puzzle is located Here. Context: A reclusive billionaire has created a game show to ...
27
votes
5answers
1k views

Take It or Leave It: A Game Show for Computers

Context: A reclusive billionaire has created a game show to attract the world's best and brightest programmers. On Mondays at the stroke of midnight, he chooses one person from a pool of ...
6
votes
1answer
255 views

Cross platform… You wish

Write a program that will produce differing behaviors on as many different platforms as you can. Each differing platform awards one point (including an initial platform, meaning you can't score less ...
-6
votes
6answers
131 views

Deep thought: Levenshtein distance [duplicate]

So, blatantly plagiarizing from inspired by this challenge and its sequel, I thought I'd add another. The text to match: What do you get when you multiply six by nine The result your ...
2
votes
2answers
626 views

A Kingdom Hearts VGM challenge

I'm a huge video game music fan. One of my favorite OSTs is that from Kingdom Hearts, by Yoko Shimomura. The challenge Create a program or function that takes two arguments in any format: an ...
1
vote
0answers
75 views

Minimizing Covering Arrays

This is the followup question to this previous CodeGolf question about Covering Arrays (the details of what Covering Arrays are and how they are formatted at the NIST website are there). In this ...
12
votes
5answers
906 views

Code close to the challenge: Inception

This is a sequel to this challenge: Code close to the challenge: Sum of integers The challenge in this one is a bit harder, and also makes for a cool title (Which is why I picked it): Calculate ...
31
votes
15answers
3k views

Code close to the challenge: Sum of integers

This is a simple challenge: Given a sequence of integers, find the sum of all integers in it. But with a twist. Your score is the Levenshtein distance between your code and the following phrase (The ...
30
votes
17answers
5k views

Holy Hole In A Donut, Batman!

Holy Hole In A Donut, Batman! Some characters are more holy than others. Using as few unholy letters as possible, display the statement above. Challenge Write a full program to print Holy Hole In A ...
24
votes
2answers
912 views
+150

Shortest universal maze exit string

A maze on an N by N grid of square cells is defined by specifying whether each edge is a wall or not a wall. All outer edges are walls. One cell is defined as the start, and one cell is defined as the ...
3
votes
1answer
151 views

Path of exile map combinations

This question will feature a mechanic from the game "Path Of Exile" in this game there are things called MAPS they are items that you can use to open high level areas, you can also combine 3 of them ...
8
votes
0answers
326 views

Lossy ASCII art compression

Background PICASCII is a neat tool that converts images into ASCII art. It achieves different degrees of brightness by using the following ten ASCII characters: @#+';:,.` We'll say that these ...
13
votes
6answers
886 views

A determinant optimization challenge

Consider 30 by 30 Toeplitz matrices all of whose entries are 0 or 1. This challenge is a simple optimization challenge to find the matrix with the largest determinant possible. Input None Output A ...
5
votes
2answers
257 views

Conversion to Boolean satisfiability

Given a matrix M all of whose entries are 0 or 1, we want to known whether there exists a non-zero vector v with each element in {-1, 0, 1}, such that Mv = 0. An easy way to do this is just to try ...
5
votes
1answer
177 views

Most efficient table storage for determining recurrence

The goal of this challenge is to implement a storage and retrieval pattern that will most quickly determine if a set of recurrence definitions fall within a date range. Consider the schema: Event ...
0
votes
2answers
205 views

Javascript function challenge add(1,2) and add(1)(2) both should return 3 [closed]

A friend of mine challenged me to write a function that works with both of these scenarios add(1,2) // 3 add(1)(2) // 3 My instinct was the write an add() function that returns itself but I'm not ...
33
votes
8answers
5k views

40 Numbers in 9 Bytes

There are 40 ways a directed Hamiltonian path can be arranged on a 3×3 grid: This graphic (thanks Sp3000!) shows only the 20 undirected paths. Traverse each colored line in both directions for ...
3
votes
0answers
188 views

Write a Compiler [closed]

Write a compiler, for any programming language you like, which need not be a serious programming language. To make things simple, it is possible for you to implement the compiler for a minimal subset ...
-4
votes
9answers
287 views

Generate and print the first 20 Fibonacci numbers with the least unique characters

As the title suggests, my task is fairly straightforward: Write a program in your language of choice that will print out the first 20 Fibonacci numbers using the least unique characters. For example ...
1
vote
1answer
196 views

Quine permutation group

Write a program or function which, when run, outputs another program or function which is valid in the same language as the original program, and which itself will output another program or function ...
25
votes
8answers
1k views

Uniquely separated pixels

For an N by N image, find a set of pixels such that no separation distance is present more than once. That is, if two pixels are separated by a distance d, then they are the only two pixels that are ...
41
votes
23answers
5k views

First code golf decathlon

Tasks All competitors try to solve the following list of 10 tasks: math Read a positive integer n from input and return the sum of the cubes of the first n non-negative integers. For input 1, ...
16
votes
2answers
3k views

Prime Nerd Sniping Pattern

Longest day of the year - here's something to waste the extra time... Overview Note this is not a popularity contest and not a graphical output challenge - you are only required to output a string ...
17
votes
3answers
483 views

Stacking Pythagorean Triangles

Background A Pythagorean triangle is a right triangle where each side length is an integer (that is, the side lengths form a Pythagorean triple): Using the sides of this triangle, we can attach ...
34
votes
4answers
819 views

Build a one-word search generator

The word BANANA appears exactly once in this word search: B A N A A N B B A B A N A B A N A N A B N N A A N N B A A A N N N A A N N N B A A N N N B A N A N A A B A N A N B A N A N B B A The word ...
42
votes
6answers
4k views

1 character typo generating most error messages from C++ compilation

It seems that simple changes to a C++ file, especially with templates, can generate pages of errors. This contest is to see what the largest "bang of the buck" is, that is the more verbose error ...
16
votes
5answers
654 views

Boggle Board Compression

When working on Non-Palindromic Polyglot Boggle, I found it quite tedious to pack the codes as efficiently as possible onto the Boggle board, even with only two strings. But we're programmers, right? ...
6
votes
2answers
365 views

Coding hex board game

Introduction Hex is a strategy board game played on a hexagonal grid, theoretically of any size and several possible shapes, but traditionally as an 11×11 rhombus. Other popular dimensions are 13×13 ...
13
votes
1answer
762 views

Rearranging Words

You should write a program which receives two strings as input and outputs a sequence of movements which rearrange the first string into the second. You should use as few moves as you can. Both ...
10
votes
1answer
438 views

Non-Palindromic Polyglot Boggle

Introduction The number 101 is a palindrome, since it reads the same backwards and forwards. The number 105 is not. However, 105 in base eight is written as 151, which is palindromic. On the other ...
9
votes
2answers
238 views

Visit each drifting tracker

Your job is to replace the battery packs on many floating fish tracking devices in the shortest time. You must leave your base in the base helicopter and visit each tracker once, then return to the ...
0
votes
2answers
183 views

Make a valid error maker!

We've been twice challenged to make 'error quines' (see Make an error quine! and Make a slow error quine maker!), so why don't we try the opposite? Instructions Write a "program" that, when run, ...
21
votes
8answers
1k views

Make a slow error quine maker!

As part of his answer to Make an Error Quine!, @Falko proposed the following algorithm: How to create your own solution in 2 minutes? Open a new file in an IDE of your choice. Bang your ...
0
votes
0answers
98 views

The polyglot challenge! [duplicate]

A polyglot is a program which can be run by several different language's interpreters/compilers without failing. For example, the stackoverflow 404 page contains a polyglot which runs in Python, ...
13
votes
5answers
408 views

Print strings without sharing characters

Edit: Allowed to reuse whitespaces. Your task is to write n programs (or functions, or bodies of functions without using parameters or the function names) in the same language. The kth program ...
11
votes
1answer
372 views

Build a poisoned wine testing scheduler

Recently at Puzzling.SE, there was a problem that I wrote about determining which two bottles out of a larger number are poisoned when the poison only activates if both components are drunk. It ended ...
18
votes
7answers
539 views

Optimize the Scralphabet

Scralphabet A normal bag of Scrabble tiles contains the following letters (? is a blank tile, which can stand for any other letter): ...
7
votes
10answers
641 views

List Sophie Germain primes

The Question A Sophie Germain prime is a prime p such that 2p+1 is prime as well. For example, 11 is a Sophie Germain prime because 23 is prime as well. Write the shortest program to calculate Sophie ...
12
votes
1answer
210 views

Express a number - a modern “Des Chiffres et des Lettres”

Express a number Back in the 60s, the French invented the TV game show "Des Chiffres et des Lettres" (Digits & Letters). The goal of the Digits-part of the show was to come as close as you can to ...
4
votes
4answers
505 views

Many programs, few characters

Your task is to create many programs. The first outputs 1, the second outputs 2, etc. The higher you can go, the better! However, all of these programs must be made the same list of characters. You ...
15
votes
6answers
388 views

Princely Prefix by a Program in Pattern

You should write a program or function which outputs or returns as much of Chapter I of The Little Prince as it can. Your program or function has to be an M-by-N block of code containing only ...
42
votes
125answers
4k views

Evolution of OEIS

In this challenge, the goal is to recreate the On-Line Encyclopedia of Integer Sequences one sequence at a time. Similar to the Evolution of Hello World, each answer depends on a previous answer. ...
7
votes
3answers
621 views

Matrix property X revisited (or the Joy of X)

This challenge is partly an algorithms challenge, partly an optimization challenge and partly simply a fastest code challenge. A T matrix is fully specified by its first row r and first column c. ...
1
vote
2answers
369 views

Write an Antiquine [closed]

Definitions: I define a "true antiquine" as follows: A true antiquine is a non-empty computer program of length n which takes no input and produces a copy of every valid program of length n in ...
15
votes
4answers
954 views

Make the largest infinity that you can!

The ordinal number system is a system with infinite numbers. A lot of infinite numbers. So many infinite numbers that it literally does not have an infinity to represent its own infiniteness. The ...
6
votes
3answers
3k views

Getting a Highscore in Kuku Kube [closed]

First of all, this is more a challenge, than a serious programming question, I would like to share. Some of you might know the game Kuku kube, where you have to identify a square in a grid, which has ...
1
vote
4answers
582 views

Memory is Expensive [closed]

You are a robot. You are stranded in a small cage with weird humans wearing weird suits looking at you. Your solar panel is malfunctioning, and your energy is running out. On the wall there is a ...
-2
votes
4answers
207 views

Write a program that takes as close to 1 second sharp to execute in your language [closed]

Write a program that takes as close to 1 second Wall-time sharp to execute in your language. Anything goes except to have the processor sleep / pause / wait, by either internal or relying on external ...
9
votes
4answers
501 views

Build a minimum-clue Sudoku unsolver

My attempt at stating this question, but with a more objective solving criterion. Your task is to build a program or function that takes a solved Sudoku grid S in the format of your choice and ...
18
votes
2answers
2k views

Brainf*** subprograms with unique outputs

You should write a 100-byte long brainfuck (BF) program. One character will removed from it in every possible way the resulting 100 new (99-byte long) programs. E.g. for the program ++.>. the 5 ...