Questions tagged [code-golf]

Code-golf is a competition to solve a particular problem in the fewest bytes of source code.

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36 votes
18 answers
6k 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 ...
Thomas O's user avatar
  • 3,348
6 votes
0 answers
785 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 ...
Alexandru's user avatar
  • 6,154
9 votes
15 answers
826 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 ...
fR0DDY's user avatar
  • 4,577
9 votes
10 answers
667 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\$ ...
fR0DDY's user avatar
  • 4,577
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. ...
Thomas O's user avatar
  • 3,348
8 votes
8 answers
450 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. ...
fR0DDY's user avatar
  • 4,577
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 ...
Michael Kohl's user avatar
15 votes
4 answers
5k 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, ...
Joey Adams's user avatar
  • 10.6k
38 votes
7 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 ...
Hoa Long Tam's user avatar
  • 2,092
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: ? ...
Ming-Tang's user avatar
  • 5,969
16 votes
4 answers
32k 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: ...
Mike Grace's user avatar
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 ...
ChristopheD's user avatar
  • 1,719
41 votes
12 answers
11k 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 ...
Joey's user avatar
  • 13k
14 votes
9 answers
835 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 ...
Eelvex's user avatar
  • 5,512
9 votes
9 answers
876 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 ...
Thomas O's user avatar
  • 3,348
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 ...
gnibbler's user avatar
  • 15.1k
30 votes
47 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 ...
C. K. Young's user avatar
  • 4,947
25 votes
13 answers
6k 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. ...
snmcdonald's user avatar
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 ...
Alexandru's user avatar
  • 6,154
18 votes
52 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 ...
Kyle Rosendo's user avatar
80 votes
53 answers
36k 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 ...
grokus's user avatar
  • 1,287
28 votes
4 answers
3k views

Implement a Non-Guessing Sudoku Solver

Implement the shortest Sudoku solver. Sudoku Puzzle: ...
snmcdonald's user avatar
34 votes
55 answers
7k 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 ...
Kevin Brown-Silva's user avatar
8 votes
4 answers
587 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 ...
PleaseStand's user avatar
  • 5,617
9 votes
10 answers
3k 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 ...
dmckee --- ex-moderator kitten's user avatar
137 votes
145 answers
44k 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 ...
Kevin Brown-Silva's user avatar
17 votes
44 answers
6k 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 ...
Daniel Standage's user avatar
52 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 ...
sepp2k's user avatar
  • 1,869
33 votes
20 answers
14k 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 ...
PleaseStand's user avatar
  • 5,617
67 votes
140 answers
12k 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 ...
Thomas O's user avatar
  • 3,348
50 votes
48 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 ...
user avatar
19 votes
12 answers
890 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 ...
Keith Randall's user avatar
18 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 ...
moinudin's user avatar
  • 12.7k
15 votes
4 answers
1k 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++?
53 votes
50 answers
8k 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. "...
Joey's user avatar
  • 13k
36 votes
16 answers
25k 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. ...
Joey's user avatar
  • 13k
6 votes
33 answers
3k views

Print largest integer you can with the fewest characters [closed]

Find a way to output a large integer with few characters. Solutions will be scored based on the magnitude of the number and shortness of code. EDIT: Let's impose a time limit of a minute on sensible ...
moinudin's user avatar
  • 12.7k
28 votes
37 answers
3k views

Finding "sub-palindromes".

The shortest code that finds all unique "sub-palindromes" of a string, that is: any substring with length > 1 that is a palindrome. eg.1 ...
Eelvex's user avatar
  • 5,512
76 votes
59 answers
20k views

Tips for code-golfing in C#

What general tips do you have for golfing in C#? I'm looking for ideas that can be applied to code golf problems in general that are at least somewhat specific to C# (e.g. "remove comments" is not an ...
jcolebrand's user avatar
  • 1,873
40 votes
55 answers
4k views

196 algorithm code golf

Write a short program for 196-algorithm. The algorithm starts from an integer, then adds its reverse to it until a palindrome is reached. e.g. ...
Eelvex's user avatar
  • 5,512
14 votes
1 answer
1k views

Shortest path in a graph

Write a program to take a graph (from either standard input or a file, your choice) and find a shortest path in the graph. Graphs are specified using the following format: ...
Keith Randall's user avatar
7 votes
3 answers
436 views

Compress programs

Write a program/script that decompresses and passes any compressed data appended at the end of the binary/file as standard input to a program specified as arguments. ...
Alexandru's user avatar
  • 6,154
11 votes
1 answer
740 views

Write a compressing util for gzip files

The task of this challenge is as following: Write a program that reads a file of reasonable size (let's say <16 MB) from stdin or anywhere else (however you like, but must not be hardcoded), and ...
FUZxxl's user avatar
  • 10.1k
63 votes
30 answers
20k views

Tips for golfing in C++

What general tips do you have for golfing in C++? I'm looking for ideas that can be applied to code golf problems in general that are at least somewhat specific to C++ (e.g. "remove comments" is not ...
moinudin's user avatar
  • 12.7k
38 votes
26 answers
33k views

Morse code translator

Write the shortest program to transform the standard input into Morse code. Characters not in the table should be printed as they are.
Alexandru's user avatar
  • 6,154
-3 votes
1 answer
5k views

Poisson random number generator [closed]

What is the shortest function (implemented in C) that will return a random draw from a Poisson distribution (given the mean or λ parameter)? ...
Daniel Standage's user avatar
11 votes
2 answers
4k views

Test if a given number is a Vampire Number [duplicate]

EDIT: In the interest of increasing the complexity, i've added more to the challenge. In mathematics, a vampire number (or true vampire number) is a composite natural number v, with an even ...
st0le's user avatar
  • 2,228
4 votes
5 answers
943 views

Tree traversal. [closed]

Write the shortest code that traverses a tree, breadth-first. Input any way you like Output a list of "names" of the nodes in correct order.
Eelvex's user avatar
  • 5,512
37 votes
61 answers
5k views

Sum of primes between given range

Write the shortest code for finding the sum of primes between \$a\$ and \$b\$ (inclusive). Input \$a\$ and \$b\$ can be taken from command line or stdin (space seperated) Assume \$1 \le a \le b \le ...
st0le's user avatar
  • 2,228
48 votes
41 answers
18k views

Obfuscated FizzBuzz Golf [closed]

Create the shortest possible obfuscated FizzBuzz implementation. To be considered obfuscated, it should satisfy at least one of the following: Does not contain any of the words "Fizz", "Buzz", or "...
mootinator's user avatar
  • 1,209