Questions tagged [code-golf]
Code-golf is a competition to solve a particular problem in the fewest bytes of source code.
11,174
questions
6
votes
3
answers
729
views
Word guessing game
A program should take an input on stdin, and guess what a word might be. It should run as a session. One example session is shown below. Characters are fed to it, with a * for a letter not revealed; ...
- 3,262
16
votes
5
answers
2k
views
Interpret Befunge-93
The program will be provided as the first argument, stdin should be used for all
read requests by the program and stdout for all write requests. It can be
assumed that the program is less than 80 ...
- 2,021
11
votes
18
answers
764
views
Output nearby primes
Write a program which takes an input (which may or may not be prime), and lists the immediate prime following and preceding it.
Example input:
1259
Example ...
- 3,262
29
votes
5
answers
2k
views
Advanced Calculator
You must write a program that evaluates a string that would be entered into an advanced calculator.
The program must accept input using stdin and output the correct answer. For languages that do no ...
- 6,276
89
votes
203
answers
20k
views
Find the Factorial!
Create the shortest program or function that finds the factorial of a non-negative integer.
The factorial, represented with ! is defined as such
$$n!:=\begin{...
- 6,276
4
votes
5
answers
1k
views
Tree traversal: Depth-first search
Write the shortest code that traverses a tree, depth-first.
Input
Any programmatical structure found in your language of choice: lists, tuples, queues etc.
Output
A list of "names" of the nodes in ...
- 221
51
votes
7
answers
5k
views
Robot Finds Kitten
The challenge
The shortest code by character count to help Robot find kitten in the fewest steps possible.
Golfers, this is a time of crisis - Kitten gone missing and it's Robot's job to find it! ...
- 611
30
votes
8
answers
4k
views
Self-Interpreting Interpreter
Based on a comment by George Edison to this question, write the smallest self-interpreting interpreter.
You may use the language of your choosing.
Empty languages do not count. Your program must be ...
- 2,022
25
votes
13
answers
6k
views
Assembly Language Quine
Write the shortest possible assembly-language quine.
Use any ISA you want, unless it has a print-quine instruction or equivalent. Examples include x86, MIPS, ...
- 2,022
21
votes
19
answers
4k
views
Basic Calculator
You must write a program to evaluate a string that would be entered into a calculator.
The program must accept input and output the correct answer. For languages that do not have standard input/...
- 6,276
13
votes
5
answers
626
views
Perfect powers in more than one way?
Challenge
Your task is to write a program or function which, given a positive integer \$N\$, finds all positive integers less than or equal to \$N\$ that can be expressed as a perfect power in more ...
- 4,453
20
votes
6
answers
1k
views
Fix a broken random function
A friend has an add-on card in their computer which generates a perfectly random number from 1 to 5 inclusive. Unfortunately, they spilt cola on it somehow, and it now generates only 2's for all ...
- 3,262
14
votes
18
answers
722
views
Integer to string with given radix
Write the shortest function to convert an integer into a numeric representation given a radix between 2 and 62. e.g.:
to_string(351837066319, 31) => "codegolf"
- 281
3
votes
6
answers
432
views
Minimum of last k [closed]
Write a function that takes two arguments: a number k and a list l, and that returns another list ...
- 5,906
33
votes
16
answers
4k
views
Calculate 500 digits of pi
Write a program to calculate the first 500 digits of pi, meeting the rules below:
It must be less than 500 characters in length.
It cannot include "pi", "math.pi" or similar pi constants, nor may it ...
- 3,262
7
votes
0
answers
775
views
Stable positive/negative separation [closed]
From SO.
You are given an array with positive and negative integers. Write a function to change the elements order in the array such that negative integers are at the beginning, the positive integers ...
- 5,906
6
votes
11
answers
592
views
Find the largest value of power.
Some numbers can be represented as perfect powers of other numbers. A number x can be represented as x = base^power for some integer base and power.
Given an integer x you have to find the largest ...
- 4,453
9
votes
10
answers
653
views
Find the number of x-digit numbers whose product of digits is N
Given two numbers \$N\$ and \$x\$, find the number of \$x\$-digit numbers whose product of digits is \$N\$
\$N <10^6\$ and \$x <12\$
...
- 4,453
15
votes
28
answers
3k
views
Implement division
Implement a division algorithm in your favourite language which handles integer division. It need only handle positive numbers - but bonus points if it handles negative and mixed-sign division, too. ...
- 3,262
8
votes
8
answers
440
views
Remainder When N divided by 2^M
Write the shortest code to find the remainder when an input number N is divided by 2^M. You cannot use /,* and % operator.
...
- 4,453
24
votes
20
answers
2k
views
Chris Pine's "Deaf Grandma"
I'm a mentor at RubyLearning and one of the exercises we give to our students is the "Deaf Grandma" exercise from Chris Pine's book "Learn to Program". Here's the description:
Write a Deaf Grandma ...
- 503
14
votes
4
answers
4k
views
Write a JSON validator [closed]
Write a program that determines whether its input is valid JSON.
Input: ASCII text: [\x00-\x7F]*
Note: if ASCII is problematic, feel free to use another encoding, ...
- 10.4k
37
votes
8
answers
4k
views
Self-compiling compiler [closed]
This is based on a talk on compilers I listened to a while back, but I, unfortunately, can't remember when or where.
Create the shortest compiler in any language that can compile itself. Target any ...
- 2,022
16
votes
12
answers
2k
views
Implement glob Matcher
Implement a function of pattern and string to be matched, return true if the pattern matches the WHOLE string, otherwise false.
Our glob pattern syntax is:
? ...
- 5,831
16
votes
4
answers
31k
views
Shortest URL regex match in JavaScript [closed]
Create the shortest regular expression that will roughly match a URL in text when run in JavaScript
Example:
...
- 271
12
votes
8
answers
2k
views
Build a nine-level word guessing game
The basics:
You'll need to provide a nine-level word guessing game in the fewest characters possible (in your language of choice).
The metrics:
Provide a word-list
(one word per line, seperated by a
...
- 1,659
40
votes
12
answers
8k
views
Drawing a gradient in ASCII art
Task description:
Write a program as short as possible to draw a radial gradient in ASCII art. The size of the output grid is predefined. The center point and the characters to be used for the ...
- 12.8k
14
votes
8
answers
787
views
Calculating areas.
The smallest code that gives the area between the curve p(x) = a0 + a1*x + a2*x2 + ..., the line y = 0, the line x = 0 and the line x = C
(i.e. something like this:
)
You can assume that p(x) >= 0 ...
- 5,438
9
votes
9
answers
863
views
Split a word into parts with equal scores
Assuming A=1, B=2... Z=26, and the value of a word is the sum of these letter values, it is possible to split some words into two pieces such that they have equal values.
For example, "wordsplit" can ...
- 3,262
13
votes
10
answers
1k
views
Forecast the weather
Write the shortest program to forecast the weather for the next 7 days
The input (from stdin) is the weekday and the season
The output (to stdout) is seven lines weekday and the temperature in ...
- 14.9k
29
votes
44
answers
3k
views
Implement Bogosort
Is solving Sudoku too hard? Even the brute force version? Here's a coding exercise that's a little easier. I hope. :-P
Write the shortest function to implement bogosort. In specific, your function ...
- 4,847
23
votes
13
answers
5k
views
Implement a Brute Force Sudoku Solver
Implement the shortest Sudoku solver using guessing. Since I have received a few request I have added this as an alternative question for those wishing to implement a brute force sudoku solver.
...
- 687
9
votes
1
answer
2k
views
Build an engine for a maze game
This is a follow up of Print a maze question. If you like this question, please add more maze generation algorithms ;).
For this task you'll have to implement a game engine for one player who must ...
- 5,906
17
votes
48
answers
2k
views
IPv4 Integer Conversion Function
Write the shortest function to convert an IP address into it's integer representation and output it as an integer.
To change an IPv4 address to it's integer representation, the following calculation ...
- 291
76
votes
53
answers
29k
views
Tips for golfing in Ruby
What general tips can you give for golfing in Ruby?
I'm looking for ideas that can be applied to code golf problems in general that are specific to Ruby. (For example, "Remove comments" would not be ...
- 1,247
27
votes
4
answers
3k
views
30
votes
49
answers
6k
views
Calculate ISBN-13 check digit
Write a function which, given the first 12 digits of an ISBN-13 code, will calculate the entire ISBN via calculating and appending an appropriate check digit.
Your function's input is a string ...
- 6,276
8
votes
4
answers
567
views
Binary search ("bisect") tool
Implement the binary search algorithm as used to identify the source code revision that breaks a computer software program. Your tool should take two arguments specifying the earliest and latest ...
- 5,557
9
votes
10
answers
2k
views
Crossword numbering
Produce a program to correctly number a crossword grid.
Input
The input will be the name of a file representing the crossword
grid. The input filename may be passed as an argument, on the
standard ...
131
votes
136
answers
42k
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:
Does ...
- 6,276
15
votes
41
answers
5k
views
Shortest Floor Function
Your task is to implement a floor function in as few bytes as possible.
A floor function is a function that takes a real number and returns the largest integer less than or equal to the input.
Your ...
- 714
48
votes
11
answers
16k
views
Write an interpreter for the untyped lambda calculus
The challenge is to write an interpreter for the untyped lambda calculus in as few characters as possible. We define the untyped lambda calculus as follows:
Syntax
There are the following three ...
- 1,769
30
votes
19
answers
13k
views
Twinkle Twinkle Little Star
Write a program to play the popular English nursery rhyme.
(This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. Attribution: Helix84 at the English language ...
- 5,557
63
votes
121
answers
10k
views
Reverse stdin and place on stdout
Requirements:
Take an input on stdin including new lines / carriage returns of unlimited length (only bounded by system memory; that is, there is no inherent limit in the program.)
Output the reverse ...
- 3,262
44
votes
43
answers
10k
views
Reverse Polish notation
You must evaluate a string written in Reverse Polish notation and output the result.
The program must accept an input and return the output. For programming languages that do not have functions to ...
user11
18
votes
12
answers
861
views
Compute modular inverse
Given two positive numbers \$x\$ and \$n\$ with \$x<2^n\$, write the shortest possible function to compute \$x^{-1} \mod 2^n\$. In other words, find \$y\$ such that \$xy=1 \mod 2^n\$.
Your ...
- 20.5k
17
votes
2
answers
1k
views
Slot Machine Hacker
Problem: Slot Machine Hacker from Facebook Hacker Cup 2011 Round 1B
Goal: Shortest code in your favourite language using stdin/stdout. You cannot assume ...
- 12.2k
15
votes
4
answers
956
views
Freely available books for code golfing? [closed]
Can you recommend any freely available books about code golfing in general and especially in Java and C++?
49
votes
49
answers
7k
views
Tips for golfing in PowerShell
What general tips do you have for golfing in Windows PowerShell? I'm looking for ideas that can be applied to code golf problems in general that are at least somewhat specific to PowerShell (e.g. "...
- 12.8k
33
votes
14
answers
19k
views
Drawing a cube in ASCII art
Task description:
Draw a cube in ASCII art in roughly a cabinet projection.
Monospaced fonts often have characters that are about twice as high as they are wide. ...
- 12.8k