A code challenge is a competition for creative ways to solve a programming puzzle for an objective criterion other than code size. Challenges to produce the shortest working code should be tagged [tag:code-golf].
1
vote
1answer
60 views
Floating points: Make Gaussian elimination go wrong
You know that some decimal numbers can't be expressed as IEEE 754 floating points. You also know that arithmetic with floating points can give results that seem to be wrong:
...
-5
votes
2answers
159 views
Beer Friday Challenge #1: Dynamic conditional puzzle [closed]
Solve,
((15, 'less_than', 30) == true)
Use any language you are comfortable with. The only thing you must not do is mentally substitute the words for the symbols.
Here's a link to the gist if you ...
-2
votes
0answers
67 views
Build a reusable, customizable menu widget using angularjs [closed]
Build a reusable, customizable menu widget using angularjs that allows you to have as many levels as you like and is reusable in the vain of:
Sudo code:
-- ul template
ul template open
for each in ...
3
votes
4answers
276 views
Encode a program with the fewest distinct characters possible,
The goal is to write a program that encodes an other program (input) with the fewest character possible.
Scoring
The score is equal to the different number of characters needed for the output.
...
-3
votes
2answers
175 views
Search for all the possible permutations of one String in another string
Suppose you are given two strings like
String 1 = "ipsum"
String 2 = "Lorem ipsum is simply dummy text of the printing and typesetting industry.
Lorem sipum has been the industry's standard ...
2
votes
7answers
448 views
Compute the number of ways how you can express a number as a sum
For a given natural number n, compute the number of ways how one can express n as a sum of positive natural numbers. For example, for n = 1 there is just one way. For n = 4 we have 5 possible ways:
1 ...
6
votes
5answers
306 views
Avoid duplicate entries using a sign change
This anecdote contains the following intriguing exchange:
"Fine, Fred," Avi interrupted. "Then how would you change this to avoid duplicate entries?"
"Oh, just change that one there to a negative ...
2
votes
0answers
209 views
Write a Polish notation interpreter, then change it to RPN in shortest number of chars
Write a program to convert Polish prefix notation to infix notation, then change it to an RPN-to-infix converter in the shortest number of chars.
Your score is 100 minus the number of characters ...
2
votes
5answers
450 views
Challenge: take ciphered text and decipher, also print out if it was offset to the left or right
Problem:
Take input text like this: (all input should be considered strings)
Upi djpi;f ytu yu[omh pmr yp yjr ;rgy.
And figure out if it was offset left or offset right (on a standard qwerty ...
51
votes
52answers
5k views
-ENDED- Do something that looks like something else
Write a snippet, a function, a programm, ... that is obfuscated in a way that it looks clear at the first sight that it does something else.
For example: write a bit of code that adds two number, but ...
6
votes
4answers
374 views
Display a bézier curve in the browser
The goal is to display a bézier curve in any classical browser (except maybe old IE versions, because... are they really browsers?) client side.
Rules:
You must provide one or more files (or their ...
23
votes
5answers
1k views
Fault-Tolerant Hello World (a.k.a. the Interview)
At the end of your interview, the Evil Interviewer tells you, "We make all of our applicants take a short coding test, to see if they really know what they are talking about. Don't worry; it's easy. ...
24
votes
24answers
2k views
Print a string in as few distinct characters as possible
The task is simple: print The quick brown fox jumps over the lazy dog using as few distinct characters in your source code as possible.
print "The quick brown fox jumps over the lazy dog" has a score ...
3
votes
9answers
387 views
Eight Queens Obsfucation
You've probably heard of the classic Eight Queens Puzzle. For those of you who haven't it goes something like this:
Position 8 queens on an 8×8 chessboard so that no two queens threaten
each ...
7
votes
3answers
265 views
Rosetta Stone Challenge: Draw a Box Plot
The goal of a Rosetta Stone Challenge is to write solutions in as many languages as possible. Show off your programming multilingualism!
The Challenge
Your challenge is to implement a program that ...
15
votes
4answers
978 views
(Re)Implementing Tetris
In the spirit of re-implementing classic video games, I would like to invite the community to create their best implementation of Tetris.
For reference, a screenshot of the official NES version of ...
7
votes
1answer
337 views
Generate a number by using a given list of numbers and arithmetic operators
You have a list of numbers L = [17, 5, 9, 17, 59, 14], a dictionary of operators O = {+:7, -:3, *:5, /:1} and a number N = 569.
Task
Output an equation that uses all numbers in L on the left-hand ...
-2
votes
3answers
331 views
Write a program to print squares of integers up to 25 in java without using variables?
I asked this question on programmers 10 days back but wasn't able to get the answer that I wanted.
Write program in java to print the squares of first 25 integers(1-25) without using any variables.
...
1
vote
1answer
226 views
Build a 12-hour digital clock
In my essay "Use the 24-hour clock", I claim that trying to represent the 12-hour clock directly in data is a terrible exercise in patchy, inelegant programming:
"No problem, we'll just use ...
12
votes
5answers
709 views
Find largest prime which is still a prime after digit deletion
Over at http://math.stackexchange.com/questions/33094/deleting-any-digit-yields-a-prime-is-there-a-name-for-this the following question is asked. How many primes are there that remain prime after you ...
9
votes
5answers
551 views
Swapping numbers
This is a common puzzle many of you have solved manually. Now this is the time to write an algorithm to solve the same.
There are equal number match sticks lined up in two different side facing each ...
5
votes
2answers
347 views
Drawing 3d nets - Archimedean solids
I have a weakness for 3d nets which when cut out and folded allow you to make 3d shapes out of paper or card. The task is simple, written the shortest program you can that draws nets for the 13 ...
7
votes
4answers
699 views
Breakout in half an hour
When I was a young teen I had a very boastful friend who claimed he could code up breakout (http://en.wikipedia.org/wiki/Breakout_(video_game)) in half an hour. Half an hour later he had done a great ...
7
votes
8answers
793 views
Write ASCII-Art Obfuscated Code, read as, and resulting in: “DFTBA”
The challenge is to write the most elaborate code, embedded in ASCII art that reads and prints "DFTBA". For example, the following reads DFTBA:
oooooooooo. oooooooooooo ooooooooooooo oooooooooo. ...
5
votes
2answers
674 views
Bouncing ball simulation
Print, on STDOUT, a pattern which shows in what direction a bouncing ball will take.
The following assumptions are made:
The ball starts at the top left corner: 0, 0 with zero initial velocity.
...
-2
votes
1answer
250 views
Emulate an Intel 8086… COMPLETELY [duplicate]
Possible Duplicate:
Emulate an Intel 8086 CPU
I know that there already is a code golf for this, but that one didn't require much. This one, however, is for masochists only! >:) OK, you ...
16
votes
7answers
623 views
Find The Wordiest Combination Lock
I have a combination padlock which has letters instead of numbers. It looks like this: http://pictures.picpedia.com/2012/09/Word_Combination_Padlock.jpg There are 5 reels, each of which has 10 ...
17
votes
9answers
1k views
Write the longest sentence using keywords of a programming language
This is not exactly a programming challenge, but a programming-related word challenge. If this is not fit for the site then feel free to close.
As the title said, the challenge is to write the ...
8
votes
1answer
300 views
Compact a Befunge program
Befunge is a 2-dimensional esoteric programming language. The basic idea is that (one-character) commands are placed on a 2-dimensional grid. Control flow walks across the grid, executing commands it ...
0
votes
7answers
480 views
Implementing bool() without any conditionals
Title says it all. Given some input, turn it into a boolean value (0 or 1), without using conditional statements (e.x. == > < <= >= != ~=), or any function which uses conditional ...
9
votes
7answers
478 views
C: replace AES FIPS-197 SubBytes table by constant-time code
In FIPS-197 (the Advanced Encryption Standard, known as AES), it is made heavy use of SubBytes, which could be implemented as
unsigned char SubBytes(unsigned char x) {
static const unsigned char ...
1
vote
4answers
347 views
Four weights to produce integer scale differences from 0 through 40 pounds
Just-in-time edit: I decided to reveal part of the answer and highlight a single aspect of the challenge.
Show how 4 weights, of 1, 3, 9, and 27 lbs. can be used to produce "weight differences" ...
3
votes
2answers
278 views
Pseudosort a list in 2*n comparisons
Write a program that takes a list of n space-separated integers, and outputs a permutation of that list using a maximum of 2*n comparisons.
It should loop this until an empty line is input. ...
3
votes
2answers
287 views
Write a java code to detect the JVM version
The objective is to write java code that detects the JVM version relying in compatibility changes, side effects, bugs and/or undefined behavior that works in a way in one version and another way in ...
3
votes
3answers
406 views
Secret Santa Challenge [duplicate]
Possible Duplicate:
Holiday Gift Exchange
Background:
Secret Santa is a Western Christmas tradition in which members of a group or community are randomly assigned a person to whom they ...
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votes
1answer
234 views
Write a program that becomes slower when a single line is added [closed]
Write a program that become much, much slower on the addition of a line of code.
Rules:
No sleep( ) statements, please.
No loops with huge LCVs.
As always, may the shortest win!
2
votes
0answers
270 views
Best Scoring Scrabble Board
Challenge
Your challenge is simply to write a program in the language of your choosing that when run, determines the highest possible score for a board of Scrabble - For the sake of this challenge, a ...
-3
votes
7answers
336 views
Swap 2 objects, without using a temporary variable [closed]
There are two objects:
Object1, Object2
You can easily swap them by:
Object3 = Object1
Object1 = Object2
Object2 = Object3
However, you must solve this problem by using no temporary object and ...
3
votes
2answers
268 views
Compiled quine variant
Thinking about various quine puzzles here, I got an idea for another one:
Compose a program that outputs its own compiled code to a file (or multiple files, if the compiled code is). (This means that ...
5
votes
3answers
648 views
Create a C program that takes the longest period of time to compile in gcc
Create a short C program that takes an absurdly long time to compile with gcc. Entries will be scored by timing the compilation then subtracting the reference program's compile time.
Rules
Any C ...
7
votes
4answers
396 views
Program my microwave oven
I'm very lazy so I try to always program my microwave with the fewest possible button presses. My microwave has the following buttons:
A "minute plus" button which may only be pressed first and ...
-5
votes
2answers
290 views
Implementing a Traffic Light Checker
A three-color traffic light must switch lights in the following order: red, green, yellow, red.
To indicate when crossing slowly without a stop is permitted, the yellow signal may be flashed. To ...
3
votes
4answers
601 views
RPN calculator without pointers
Me and some other students were at a bar discussing programming languages, in particular the C programming language. At some point a first year student said he didn't need no damn pointers. Another ...
5
votes
2answers
530 views
Domino Effect Problem
Last week we had a programming contest in my university and I am very curious about one of the problems , one which only one team (but from another city) was able to solve. May be its not that hard, ...
2
votes
3answers
334 views
m3ph1st0s's programming puzzle 4 (C/C++): “3-way swap”
My last puzzle has generated some confusion and controversy so I decided to give up, for now, on those "replace one character"-type puzzles.
Hope this 4th puzzle will redeem myself after all the ...
10
votes
1answer
559 views
Recreate an xkcd graph procedurally with your favorite plotting tool
Lately there have been quite a number of questions regarding the recreation of xkcd-style graphs like the following one (1064) in various languages.
Your goal is to recreate any existing xkcd comic ...
7
votes
2answers
441 views
m3ph1st0s's programming puzzle 3 (C): “Easy bug”
This is the 3rd of my series of C/C++ puzzles; in case you missed the first 2 they are here:
(1) m3ph1st0s's programming puzzle 1 (C++)
(2) m3ph1st0s's programming puzzle 2 (C++): "Call ...
0
votes
0answers
181 views
My Language is Better Than Yours! [closed]
this is a For-Fun challenge. The challenge is pretty simple, and one that for once, I don't think golfscript or anything similar has a chance to win!
The goal is simple, write code in whatever ...
2
votes
4answers
313 views
m3ph1st0s's programming puzzle 2 (C++): “Call hard!”
I am back with a brand new puzzle for C/C++ addicts. Following the feedback received on the 1st puzzle, this time I will try to make the requirements crystal clear and to provide a perfectly valid ...
16
votes
13answers
1k views
m3ph1st0s's programming puzzle 1 (C++)
Hello C++ programmers!
This is the first of a series of C++ puzzles for you. Hope you will enjoy.
So, puzzle no.1:
Given the following program:
#include <iostream>
int main()
{
const int ...
