Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [code-golf]

Code-golf is a competition to solve a particular problem in the fewest bytes of source code. If you want to score by characters instead of bytes, please state this explicitly in the challenge. If source code length is not the primary scoring criterion, consider using another tag instead.

26
votes
40answers
4k 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 ...
8
votes
4answers
496 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 ...
9
votes
10answers
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 ...
118
votes
118answers
35k 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 ...
7
votes
26answers
2k 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 ...
41
votes
11answers
12k 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 ...
27
votes
15answers
10k 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 ...
55
votes
90answers
7k 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 ...
39
votes
40answers
6k 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 ...
16
votes
8answers
609 views

Compute modular inverse

Given two positive numbers x and n with x<2^n, write the shortest possible function to ...
16
votes
2answers
912 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 ...
14
votes
4answers
757 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++?
43
votes
37answers
4k 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. "...
32
votes
13answers
11k 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. ...
6
votes
33answers
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 ...
21
votes
25answers
2k 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 ...
55
votes
45answers
12k 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 ...
34
votes
43answers
3k 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. ...
12
votes
1answer
878 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: ...
6
votes
3answers
352 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. ...
11
votes
1answer
627 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 ...
42
votes
21answers
11k 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 ...
28
votes
22answers
9k 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.
-1
votes
1answer
4k 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)? ...
14
votes
2answers
2k views

Test if a given number is a Vampire Number

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 ...
7
votes
5answers
775 views

Tree traversal.

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.
26
votes
42answers
3k views

Sum of primes between given range

Write the shortest code for finding the sum of primes between a and b (inclusive). Input a ...
50
votes
41answers
14k 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 "...
107
votes
211answers
22k views

Fibonacci function or sequence

The Fibonacci sequence is a sequence of numbers, where every number in the sequence is the sum of the two numbers preceding it. The first two numbers in the sequence are both 1. Here are the first ...
105
votes
49answers
14k views

Interpret brainf***

Write the shortest program in your favourite language to interpret a brainfuck program. The program is read from a file. Input and output are standard input and standard output. Cell size: 8bit ...
24
votes
38answers
3k views

Reimplementing square root [duplicate]

Define a function, s, which takes a number and returns the square root. No use of library functions, such as Java's Math.sqrt() or PHP's built in sqrt(), allowed.
181
votes
297answers
38k views

Golf you a quine for great good!

Using your language of choice, golf a quine. A quine is a non-empty computer program which takes no input and produces a copy of its own source code as its only output. No cheating -- that means ...
230
votes
136answers
67k views

Tips for golfing in Python

What general tips do you have for golfing in Python? I'm looking for ideas which can be applied to code-golf problems and which are also at least somewhat specific to Python (e.g. "remove comments" is ...
35
votes
21answers
6k views

Angle between the hands on a clock

Given the time in 24 hour format (2359 = 11:59pm) return the angle between the minute and hour hands on a standard clock (on the ...
43
votes
39answers
4k views

The Luhn algorithm for verifying credit card numbers, etc

Challenge Write the shortest program or function to calculate the Luhn Algorithm for verifying (credit card) numbers. Luhn algorithm explained From RosettaCode, this algorithm for the purposes of ...
14
votes
7answers
3k views

Hamming numbers

Given a positive integer, print that many hamming numbers, in order. Rules: input will be a positive integer such that n <= 1,000,000 execution time must be < 1 minute This is Code Golf, ...
32
votes
44answers
4k views

ROT-13 transform standard input

The challenge: To read an input of arbitrary length and produce the ROT13 of the input. All characters besides A-Z should be copied to the output verbatim, and case should be preserved if possible. ...
82
votes
85answers
12k views

Code Golf Christmas Edition: How to print out a Christmas tree of height N

Given a number N, how can I print out a Christmas tree of height N using the least number of code characters? ...