Questions tagged [code-golf]

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

Filter by
Sorted by
Tagged with
64 votes
124 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 ...
  • 3,272
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 ...
's user avatar
18 votes
12 answers
864 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 ...
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 ...
  • 12.3k
15 votes
4 answers
961 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
20k 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
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 ...
  • 12.3k
25 votes
35 answers
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 ...
  • 5,438
71 votes
56 answers
18k 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 ...
  • 1,783
38 votes
53 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. ...
  • 5,438
13 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: ...
6 votes
3 answers
425 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. ...
  • 5,936
11 votes
1 answer
719 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 ...
  • 9,970
61 votes
29 answers
17k 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 ...
  • 12.3k
35 votes
26 answers
30k 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.
  • 5,936
-1 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)? ...
12 votes
2 answers
3k 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 ...
  • 2,140
5 votes
5 answers
906 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.
  • 5,438
33 votes
52 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 ...
  • 2,140
48 votes
41 answers
17k 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 "...
  • 1,189
148 votes
310 answers
39k 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 ...
  • 4,877
138 votes
67 answers
22k views

Interpret brainfuck

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 ...
  • 5,936
24 votes
38 answers
4k 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.
  • 1,145
234 votes
417 answers
59k 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 ...
  • 2,617
321 votes
169 answers
123k 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 ...
  • 12.3k
39 votes
21 answers
7k views

Angle between the hands on a clock [duplicate]

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 ...
  • 1,009
57 votes
57 answers
8k 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 ...
26 votes
12 answers
5k views

Hamming numbers

Hamming numbers are numbers which evenly divide a power of 60. Equivalently, their prime factors are all \$ \le 5 \$. Given a positive integer, print that many Hamming numbers, in order. Rules: Input ...
  • 1,257
42 votes
60 answers
6k views

ROT-13 transform standard input

Task Read a string of characters and produce the ROT13 of it. All characters besides [a-zA-Z] should be output verbatim. Each letter in the output may be in any ...
105 votes
111 answers
18k 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? ...

1
222 223 224 225
226