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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-2
votes
0answers
42 views

Write a program that will almost always crash Windows! [on hold]

Use any language to crash Windows 7! I consider the crash to be a state that you can't do anything and you need to restart the machine. The shortest + fastest code wins! My solution: a: start goto ...
-8
votes
0answers
69 views

Produce “Happy Birthday” in output [on hold]

So, Like this code: print map(lambda x: "Happy Birthday to " + ("you" if x != 2 else "_name"),range(4)) that prints Happy Birthday in a geeky manner in python. Can anyone produce this type of ...
15
votes
1answer
715 views

Domino Circuits

Scoreboard Here are the raw scores (i.e. domino counts) for VisualMelon's submission. I'll turn these into the normalised scores described below, when more answers come in. The existing solution ...
13
votes
1answer
249 views

Horror Movie Search Party

Plot: Jimmy is missing; we have to find him. We should split up. Plot twist: Jimmy is already dead. But, our cast doesn't know that, so they need to search the whole area anyway. There is an N ...
5
votes
1answer
175 views

fit 22 (perhaps 23) of a specific 3d pentacube into a 5x5 cube

The original problem is stated here over at math.SE The task is writing a program that fits 22 copies (or perhaps 23) of the following pentacube into a 5x5x5 cube (back and front view). The ...
0
votes
0answers
91 views

Most expensive XAML code [closed]

While testing performance of various parts of my application, I came across the need to create XAML ballast that creates artificial performance bottleneck wherever I put it. For now, I am just ...
-2
votes
0answers
175 views

“Phone Dial” Encryption [closed]

A message has been encrypted in a unique (and perhaps not particularly secure) way. The characters in the message (excluding punctuation) have been replaced with their corresponding digits on a ...
39
votes
6answers
1k views

ASCII Art Calendar

Let's make an ASCII art clock and calendar that tells us the current month, day of the month, day of the week, hour, minute, and whether it's night or day (but not the year or second). At any ...
6
votes
5answers
911 views

Find the craftiest prime

Intro Consider the process of taking some positive integer n in some base b and replacing each digit with its representation in the base of the digit to the right. If the digit to the right is a 0, ...
28
votes
13answers
7k views
+100

Programming Dichotomies (Literally)

Consider a question written in plain English whose answer involves two reasonably accurate (but potentially clever) words or phrases that can be separated by the word 'and': Q: What are the two ...
-7
votes
0answers
85 views

Shortest Longest Increasing Subsequence Code

The Challenge is to write the shortest implementation to find the Longest increasing subsequence . Input: N (an integer denoting the size of the list) a_1 a_2 ... a_N (the N integers of the sequence ...
11
votes
1answer
377 views

Fusing Fireworks

Overview Given a list of fireworks a-z and times 3-78, arrange them with fuses to make them all light up at the correct time. A line of input is given as space separated letters and numbers: a 3 b ...
53
votes
15answers
3k views

Implement the Game of Life on anything but a regular grid

Conway's Game of Life is (almost) always played on a regular square grid, but it doesn't need to be. Write a program that implements the standard cell neighboring rules from Conway's Game of Life on ...
37
votes
12answers
6k views

What's the shortest contiguous subset of ASCII you need to output the rest?

The printable ASCII characters (hex codes 20 to 7E) in order are: !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~ (Note that space is in ...
7
votes
1answer
173 views

Minimal cover of bases for quadratic residue testing of squareness

Challenge Find the smallest cover of bases (e.g., moduli) whose sets of quadratic residue can be tested via table-lookup to definitively determine whether or not a given non-negative integer n is a ...
2
votes
6answers
302 views

sort and restore a set of bytes in optimal form

Challenge For any given input Y of length >= 1024 bytes: sort in ascending or descending order -- your choice generate output Q, where Q = [sorted data] + [restore information] restore Y using Q as ...
14
votes
3answers
494 views

Find the shortest bracket numbers

Bracket numbers provide a simple way to express large integers using only left bracket, space, and right bracket ([ ]). A bracket number is defined as a string of one or more pairs of matching ...
-1
votes
2answers
262 views

Find prime which is generating longest primes sequence using p(n+1)=(p(n)^2+1)/2

Consider following recurrence relation: p[n + 1] = (p[n]^2 + 1) / 2 If p[1], p[2], ..., p[k] are primes and p[k+1] is not, then k is length of sequence starting with p[1]. For example, if p[1] = 3, ...
27
votes
9answers
4k views

Find the largest prime whose length, sum and product is prime

The number 113 is the first prime whose length 3 is prime, digital sum 5 = 1 + 1 + 3 is prime, and digital product 3 = 1 * 1 * 3 is prime. A prime that has these 3 properties will be called supremely ...
22
votes
3answers
926 views

Where are the runs in this infinite string? (CCCCCC Found!)

Starting with the string ABC, consider the result of repeatedly appending the last half of itself to itself (using the larger half if the length is odd). We get the progression: ABC ABCBC ABCBCCBC ...
0
votes
0answers
7 views

Scheme - logical operator procedures [migrated]

I know Scheme and other Lisp dialects include logical operators such as 'and' and 'or', but, since I am currently learning Scheme, I am trying to program my own logical operators. So, for my attempts ...
18
votes
13answers
1k views

Khinchin's constant to as many decimal places as possible in 64 bytes or less

Khinchin's constant is a curious mathematical constant that, according to Wolfram MathWold, is "notoriously difficult to calculate to high precision". Here it is to 100 digits: ...
0
votes
2answers
382 views

Conway's Game of Life with smallest *set* of source characters [duplicate]

The goal of this challenge is to write a program that will simulate a single round of Conway's Game of Life on an existing grid. Input format: Input will be read from stdin. The input will consist ...
13
votes
2answers
493 views

Maximum number of PEP8 violations in a single line

Your task is to write a file which contains a line with many pep8 violations. The rules: We use pep8 version 1.5.7 and the default settings. Calling pep8 with other command line options or ...
3
votes
1answer
297 views

Make a Number Expression

Few years ago, an esoteric programming language named 아희(Aheui) was created. Well, actually you don't need to know about this language or Korean characters. Aheui uses stacks and a queue, but this ...
19
votes
2answers
1k views

Optimize paper folding to mitigate inkblots

Dark black ink has splattered all over your white sheet of printer paper! The obvious solution is to fold the paper so black and white parts meet and both become grey as the ink diffuses. Then unfold ...
3
votes
1answer
987 views

Optimal Minesweeper on the Largest Board

Overview: Your challenge is to write a program that will play minesweeper optimally, giving the best move in any position. Moreover, you must do this on the largest board possible. Game details: ...
0
votes
1answer
292 views

Babylon.js - loop through a scene and apply a simple fragment shader to all of the objects

You have a library - a fully loaded 2014 Babylon.js. You have a fragment shader - let's call it sample.fragment.fx. You have a scene - loaded ahead of time, possibly from a .babylon JSON file. Your ...
9
votes
3answers
439 views

mathpack numeric literals

preface In a very heated situation you have to go even further with golfing. (e.g. in a challenge where your answer is 100 characters long and it is just embarrassing that you couldn't make it 99) ...
1
vote
4answers
531 views

Rotate 2D Array [duplicate]

Given an input of a 2 dimensional array of integers, rotate the array 90 degrees clockwise. It should work for rectangular arrays of all sizes and proportions. The rotated array should be printed at ...
0
votes
1answer
419 views

Racketeer Taxi Driver

The Scenario You are a taxi driver in your city. You picked up a passenger from the airport and he told you the place he'd like to go. To earn more money, you need to drive as much as you can. ...
28
votes
5answers
2k views

To Vectory! – The Vector Racing Grand Prix

Vector racing is an addictive game that can be played with a pen and a sheet of square-ruled paper. You draw an arbitrary racetrack on the paper, define a start and end and then you steer your ...
3
votes
2answers
377 views

Deplane! Deplane! (Or: RGBRGBRGB => RRRGGGBBB?)

Imagine bytes in memory for an RGB image--R and G and B represented by bytes in sequence. If an image is NxM then the memory layout will be M repetitions for vertical scanlines of 3*N bytes in ...
18
votes
2answers
1k views

Mastermind strategy

I could only find code-golf challenges for Mastermind, so here's a code-challenge version that I would have liked to take on myself. An optimal strategy for the normal Mastermind game, MM(4,6), was ...
11
votes
2answers
497 views

Travelling Salesman

Your are given, as a list or vector or whatever, a bunch of 3-tuples or whatever, where the first two things are strings, and the third thing is a number. The strings are cities, and the number is ...
55
votes
41answers
9k views

Largest number in ten bytes of code

Your goal is to print (to the standard output) the largest number possible, using just ten characters of code. You may use any features of your language, except built-in exponentiation functions. ...
20
votes
3answers
897 views

Build a pair of spies that will throw stones into a river

Recently at the newly released Puzzling.SE, there was a problem about spies throwing stones into a river that was actually quite challenging: Two spies must pass each other two secret numbers (one ...
9
votes
0answers
556 views

Efficient error-free* encoding

The mission As is well known, the genetic material of all known creatures on Earth is encoded in DNA; using the four nucleotides adenine, thymine, cytosine, and guanine. (Commonly represented by ...
12
votes
3answers
2k views

Fastest player for Dots and Boxes

The challenge is to write a solver for the classic pencil and paper game Dots and Boxes . Your code should take two integers m and n as input which specifies the size of the board. Starting ...
18
votes
5answers
1k views

Leet to English Translation

Leet to English Translation Your challenge is to write a program to translate (English) leetspeak/lolspeak/txtspk into normal English. Your program should read from standard input and output to ...
13
votes
1answer
464 views

The Star-Spangled Code Challenge

The flag of the United States of America contains, in its canton, 50 stars, representing the 50 states. In the past, when there were fewer states, there were of course fewer stars, and they were ...
4
votes
5answers
160 views

Write biSp in point-free form using as few terms as possible

The Haskell function biSp has type signature biSp :: (a -> c) -> (b -> d) -> (c -> d -> e) -> a -> b -> e and (for those who prefer combinator calculus) can be defined as ...
-1
votes
3answers
143 views

Puzzle : Find minimum resource allocation on multiple of 10 or 12 only [closed]

I have two types of notebook . 10 problems could be solved in one page, in the first notebook. 12 problems could be solved in one page, in the second notebook. For given n problems I have to use ...
3
votes
2answers
503 views

Convert integer to string preserving order

The quest is to convert an integer to a string in such a way that 1. the order is preserved 2. using the least number of characters in the string. Let's say I have an integer X; the objective is to ...
7
votes
4answers
421 views

Build a drug testing scheduler

In this problem on Puzzling.SE, I ask a question about determining the amounts of drug to use in a clinical test to minimize total drug usage and fulfill the requirements of the testing procedure. ...
20
votes
12answers
3k views

Print the Golden Ratio

This was fun! However with only three digits, the fun was over way too soon. This challenge is similar, but we'll keep the fun going. The Challenge Print as many digits of the Golden Ratio φ as ...
18
votes
2answers
695 views

Recognize handwritten digits

Your task is to read an image containing a handwritten digit, recognize and print out the digit. Input: A 28*28 grayscale image, given as a sequence of 784 plain-text numbers from 0 to 255, separated ...
5
votes
2answers
343 views

Filter a large file in small memory

The challenge is a follow-up to Filter a large file quickly which had two submissions where were as fast as wc! This time the difficulty is that RAM is severely restricted which means that new ...
17
votes
9answers
1k views

Reverse order of words in a string inplace

The Task You are given a mutable string that matches [a-z]+( [a-z]+)*. You must mutate it into the string which contains the same words, but in reverse order, so that "hello there everyone" becomes ...
0
votes
2answers
198 views

Counting to now [closed]

This is the goal: count from 0 all the way to the current epoch time while the epoch time is still advancing in the fastest time possible. An example of how you'd do it could be as what is shown here ...