407
votes
151answers
153k views

Produce the number 2014 without any numbers in your source code

It's 2015 already, folks, go home. So, now that it's 2014, it's time for a code question involving the number 2014. Your task is to make a program that prints the number 2014, without using any ...
351
votes
103answers
60k views

Most creative way to display 42

Douglas Adams was born on March 11, 1952, and died when he was just 49. In honor of this wonderful writer, I challenge you to display 42 in the most creative way possible. Now this can be printed in ...
301
votes
119answers
152k views

Write a program that makes 2 + 2 = 5

Write a program that seemingly adds the numbers 2 and 2 and outputs 5. This is an underhanded contest. Your program cannot output any errors. Watch out for memory holes! Input is optional. ...
295
votes
56answers
74k views

Tweetable Mathematical Art

Integer math can generate amazing patterns when laid out over a grid. Even the most basic functions can yield stunningly elaborate designs! Your challenge Write 3 Tweetable (meaning 140 characters ...
292
votes
35answers
51k views

American Gothic in the palette of Mona Lisa: Rearrange the pixels

You are given two true color images, the Source and the Palette. They do not necessarily have the same dimensions but it is guaranteed that their areas are the same, i.e. they have the same number of ...
245
votes
40answers
68k views

Images with all colors

Similar to the images on allrgb.com, Make images where each pixel is a unique color (no color is used twice and no color is missing). Give a program that generates such an image, along with a ...
213
votes
32answers
29k views

Make it look like I'm working

Often, I find myself running a script or query that will take a significant amount of time to run. I can leave that script open and enjoy some guilt-free procrastination. Now, what if I could write ...
213
votes
7answers
19k views

Draw with your CPU

I have come across an article where students used network traffic to draw their university on the country's IPv6 graph. [image] Your goal is simple to tell, but hard to implement. Draw the text MAIL ...
184
votes
78answers
18k views

What? No error?

Your task is simple. Write a program that should obviously produce an error on first glance either when compiled or run, but either doesn't or produces some other unrelated error. This is a popularity ...
182
votes
53answers
24k views

Survival Game - Create Your Wolf

The Board The Board is a two dimensional array of cells. Cells are populated by Animals. Every day, all Animals on the Board simultaneously make one move. If two or more Animals move to the same ...
177
votes
75answers
20k views

Showcase your language one vote at a time [experimental challenge]

In this experimental popularity contest users will be able to showcase their favorite programming languages. However, the amount of code they are allowed to write is dependent on the number of votes ...
165
votes
168answers
24k views

Evolution of “Hello World!”

This contest is officially over, the winner is user23013. Congratulations! The challenge is to make a program that prints Hello World! to stdout. The catch is that your program must have a ...
163
votes
45answers
27k views

Trolling the troll

A troll has captured you and is forcing you to write malware (defined as a program that damages the computer that runs it). The troll can read and understand code, but is not so good at spotting bugs. ...
161
votes
11answers
14k views

DISARM THE B.O.M.B.!

You have been hired for your tech knowledge as a Secret Agent's sidekick to ensure that the good guy can get his job done and the world can be saved. This is your last mission before retiring with a ...
155
votes
57answers
8k views

Fibonacci Sequence Generator

Can you create a clever or unexpected Fibonacci generator? Your code must print or return either the nth Fibonacci number or the first n Fibonacci numbers.
148
votes
54answers
53k views

We're no strangers to code golf, you know the rules, and so do I

Write the shortest program that prints the entire lyrics of "Never Gonna Give You Up" by Rick Astley. Rules: Must output the lyrics exactly as they appear in the above pastebin. Here's the raw ...
134
votes
37answers
17k views

Write program in your favorite language in another language

The determined Real Programmer can write Fortran programs in any language. from Real Programmers Don't Use Pascal Your task is to write program in your programming language of choice, but you ...
132
votes
115answers
38k views

Weirdest way to produce a stack overflow

As a programmer you certainly know the error of a stack overflow due to an obvious recursion. But there are certainly many weird and unusual ways to get your favourite language to spit that error out. ...
130
votes
55answers
29k views

Debunking Stroustrup's debunking of the myth “C++ is for large, complicated, programs only”

Stroustrup has recently posted a series of posts debunking popular myths about C++. The fifth myth is: “C++ is for large, complicated, programs only”. To debunk it, he wrote a simple C++ program ...
127
votes
53answers
24k views

Print every character your program doesn't have

Your task is to build a program (using only printable ASCII characters and/or tabs and newlines) that prints out exactly the characters in the printable ASCII space (0x20 to 0x7e) that don't appear in ...
123
votes
49answers
56k views

Code that will only execute once

Goal The goal of this challenge is to write code that will execute once and only once. This means basically that it damages the program, script, or environment in some way. If rebooting the system ...
122
votes
53answers
11k views

Caveman Duels (or: Me poke you with sharp stick)

Caveman mad. Other caveman take stick but stick was for me. Caveman fight! Description Caveman need sharp stick to stab other caveman. Other caveman also try to stab with sharp stick. Caveman ...
116
votes
241answers
21k views

Unscramble the Source Code

Note: This challenge is now closed to new cop submissions. This is to ensure that no one can post submissions that only remain uncracked because there aren't enough robbers interested in the ...
107
votes
19answers
59k views

How slow is Python really? (Or how fast is your language?)

I have this code which I have written in Python/NumPy from __future__ import division import numpy as np import itertools n = 6 iters = 1000 firstzero = 0 bothzero = 0 """ The next line iterates ...
102
votes
51answers
25k views

Draw the Olympic Games logo

Challenge Draw the Olympic Games logo... ...as character (e.g. ASCII) art! Sample Output * * * * * * * * * * * * * * ...
102
votes
92answers
16k views

Good Versus Evil

Results - July 19, 2014 The current King of the Hill is Mercenary by user Fabigler! Keep submitting entries and knock him off of his throne! Click here to view the Scoreboard. Programs submitted on ...
102
votes
7answers
20k views

So obviously, P = NP

SAT is the problem of determining whether a boolean expression can be made true. For example, (A) can be made true by setting A=TRUE, but (A && !A) can never be true. This problem is known to ...
101
votes
63answers
16k views

Random script that isn't actually random

As a little joke in the office someone wanted a script that randomly picks a name, and said person will make a round of drinks. Let's call the people John, Jeff, Emma, Steve and Julie. I thought it ...
95
votes
10answers
17k views

Emulate an Intel 8086 CPU

Note: A couple of answers have arrived. Consider upvoting newer answers too. C from user1662116 C++ from Darius Goad Postscript from luser droog C++ from JoeFish Javascript from entirelysubjective ...
92
votes
39answers
12k views

Write a program that always outputs “2012” - even if it's modified!

This idea is not mine, though I don't know where it originated. I once met it in a programming contest very long ago (1998, if I remember correctly). The task is to write a program in your favorite ...
90
votes
24answers
9k views

Lab Rat Race: an exercise in genetic algorithms

This is Fortnightly Challenge #3. Theme: Genetic Algorithms This challenge is a bit of an experiment. We wanted to see what we could do, challenge-wise, with genetic algorithms. Not everything may be ...
88
votes
108answers
20k views

4, 8, 15, 16, 23, 42

4, 8, 15, 16, 23, 42 Write a program that outputs this sequence of numbers infinitely. However, The Numbers must not appear in your source code anywhere. The following is not a valid Java program to ...
87
votes
66answers
14k views

Why isn't it ending?

Your task: To write a program that should obviously terminate, but it never (to the extent of a computer crash) does. Make it look like it should perform a simple task: adding numbers, printing ...
87
votes
45answers
8k views

Survival Game - AlienWar

AlienWar This game takes place in a very crowded planet where aliens are the superior race. Your task is to create your own alien and beat all other. The Board It is a 2 dimensional board. The ...
85
votes
27answers
12k views

Make a scalable Christmas Tree

Your challenge: Make a Christmas tree. The size must be choosable by some input method, but doesn't have to be directly related to any part of the tree; however, larger inputs should produce a larger ...
82
votes
143answers
11k views

Execute prints backwards

Your task is to reverse the order in which some prints get executed. Specs: Your code will be in this form: //some lines of code /*code*/ print "Line1" /*code*/ /*code*/ print "Line2" /*code*/ ...
82
votes
75answers
12k views

The Rock, Paper, Scissors, Lizard, Spock Tournament of Epicness

Most Recent Leaderboard @ 2014-08-02 12:00 | Pos # | Author | Name | Language | Score | Win | Draw | Loss | Avg. Dec. Time | ...
79
votes
61answers
14k views

Tips for golfing in Python

What general tips do you have for golfing in Python? I'm looking for ideas that can be applied to code golf problems in general that are at least somewhat specific to Python (e.g. "remove comments" is ...
78
votes
31answers
13k views

If a program terminates and there is no one to see it, does it halt?

It's time to face the truth: We will not be here forever, but at least we can write a program that will outlive the human race even if it struggles till the end of time. Your task is to write a ...
78
votes
15answers
16k views

Possibly quit your job with a polyglot

Despite your protest, you have been put to work by your boss on a program that takes a single unsigned integer as input and prints the string "prime" if that integer is prime and "not prime" if it ...
77
votes
14answers
9k views

Has my milk expired?

Aww, man, this expiry date doesn't write the months with letters! I can't tell if it's expiring on March 10th or October 3rd... Wait, no, never mind, the year says 2012. (alley-oops half-used brick of ...
76
votes
42answers
20k views

Fifty Shades of Grey

Boys and girls are excited to see Fifty Shades of Grey on the silver screen, we just want to code without being bothered, so here's a challenge to pick our brain. You have to: Print on the screen ...
75
votes
92answers
14k views

When does (x == x+2)?

The challenge: Define x in such a way that the expression (x == x+2) would evaluate to true. I tagged the question with C, but answers in other languages are welcome, as long as they're creative or ...
75
votes
59answers
9k views

BrainF***edBotsForBattling - A Brainf*** Tournament

All bots at the battle arena suddenly got brainfucked and no one can explain why. But who cares as long as they are still able to fight - although Brainfuck is the only language they understand ...
74
votes
55answers
10k 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 ...
73
votes
76answers
18k views

Obfuscated Hello World

Create the shortest possible obfuscated program that displays the text "Hello World". In order to be considered an obfuscated program, it must meet at least two of the following requirements: ...
73
votes
7answers
7k views

Start a revolution in Oceania

Winners (decided 14/09/14) Winning answer by Markuz (Python) - 63 votes Runner up by kuroi neko (PHP) - 55 votes Introduction You are in the world of the book Nineteen Eighty-Four by George ...
70
votes
117answers
21k views

Loop without 'looping'

A question similar to this has been asked a couple of years ago, but this one is even trickier. The challenge is simple. Write a program (in your language of choice) that repeatedly executes code ...
70
votes
68answers
14k views

Hello world! with limited character repetition

In a language of your choice, write a program that exactly outputs the characters Hello world! followed by a newline. The code: should not use any character more than twice (alphanumeric, symbol, ...
69
votes
17answers
14k views

Undefined Behavior Killed My Cat

Undefined Behavior Killed My Cat It's well known that undefined behavior can kill your cat [citation needed]. But can it? Your Task Write a program that invokes undefined behavior. Describe a ...

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