A competition to solve a particular problem through the usage and manipulation of strings.

learn more… | top users | synonyms

18
votes
2answers
256 views

Golf Down the PPCG Usernames

A comment I made in chat and the ensuing conversation inspired me to make this challenge. Am I the only one referred to by initials around here? We are all about golfing things down. We can have ...
19
votes
6answers
1k views

A Mnemonic for Remembering 23940

The major system is a mnemonic device for converting numbers into words so they can be memorized more easily. It is based on how words sound phonetically, but to keep things simple for the challenge ...
6
votes
19answers
933 views

Write a program for splitting the string with alternative spaces

Want to write a program in minimum number of code,all programming language accepted Runtime criteria also challanged Example: Input : abcdef Output: a b c d e f ab cd ef abc def ...
12
votes
35answers
3k views

Display number of occurrences for every character in an input string

The code should take a string as input from keyboard: The definition of insanity is quoting the same phrase again and again and not expect despair. The output should be like this(not sorted in any ...
3
votes
9answers
559 views

Find The Least Common Characters

Given a string, find the 10 least common alpha-numeric characters within that string. Output should be formatted with numbers left-padded with spaces so they look like this: e: 1 t: 16 c: ...
23
votes
16answers
2k views

Shortest Unique Substrings

Input An alphanumeric string s. Output The shortest string that occurs exactly once as a (contiguous) substring in s. Overlapping occurrences are counted as distinct. If there are several ...
16
votes
8answers
1k views

Convert human readable time interval to date components

Challenge Write the shortest program that converts a human readable time interval to date components of the form: {±YEARS|±MONTHS|±DAYS|±HOURS|±MINUTES|±SECONDS} Sample cases Each test case is ...
17
votes
34answers
3k views

Convert C header names to C++ header names

In the C standard library, header names end with a .h suffix: stdio.h In C++, those header names are available in an alternative form, with a c prefix instead: cstdio Write a function that ...
20
votes
7answers
1k views

Reassuring parables

Quite a few people here are probably avid XKCD readers. So, I figure I'd challenge you guys to do something that Megan can do easily: make a script that generates thousands of reassuring parables ...
-2
votes
4answers
123 views

Extract URI parts without using libraries [closed]

Given a URI like: postgres://username:password@hostname:PORT/dbname Extract it all into an array data-structure, like so: ['postgres', 'username', 'password', 'hostname', 'PORT', 'dbname'] More ...
3
votes
2answers
245 views

Generate unique non-sequential string of length n without memory of previously generated strings

Scenario: Imagine a situation where you wish to share a unique alphanumeric code. Perhaps it is a one-time-use coupon code you hand write on business cards, or some other scenario where it is ...
38
votes
51answers
4k views

How to randomize letters in a word

According to some controversial story, the odrer of ltteres in a wrod deos not mttaer much for raednig, as lnog as the frist and lsat lteter macth with the orignial wrod. So, for fun, what would be ...
8
votes
9answers
602 views

Find Privileged Substrings

Privileged Strings The set of privileged strings is defined recursively as follows. All strings of length 0 or 1 are privileged. A string s of length at least 2 is privileged, if there exists a ...
6
votes
2answers
157 views

String Equivalence: Counting Substrings

Background Two strings s and t are called k-Abelian equivalent (shortened to k-equivalent in the following) for a positive integer k if the following conditions hold: The length-k-1 prefixes of s ...
-4
votes
5answers
180 views

How many contiguous “strings” can you find in a set of strings?

Consider the set of 16-character strings containing only the 95 printable ASCII characters. There are 9516 ≈ 4.4×1031 such strings. Imagine these strings are put into a list and sorted ...
0
votes
0answers
65 views

Find the longest recurring substring [duplicate]

Given a string of no more than 255 characters, find a function that returns the longest recurring substring. An example would be: aabbacadeauaaabba where the longest recurring sub-string is ...
16
votes
3answers
1k views

Distinguish between Masculine and Feminine Nouns in French within 100 characters

You are to write a very small program within 100 characters. Your program must distinguish between masculine and feminine french nouns. The output should be un if it is masculine and une if it is ...
14
votes
15answers
2k views

Fill In the Blanks

Input A nonnegative integer n, and a nonempty string s containing only alphanumeric characters and underscores _. The first character of s is not _. The underscores of s are interpreted as blank ...
16
votes
7answers
1k views

Typing with scrambled keys

Your friend isn't too good with computers so as a practical joke someone scrambled the letters (a-z) on his keyboard. When he sit down and tried to type his name looking at the keyboard he realized ...
10
votes
11answers
597 views

Binary encryption

This is based on xkcd #153. Make a program or named function which takes 2 parameters, each of which is a string or a list or array of bytes or characters. The second parameter will only contain ...
4
votes
3answers
359 views

Code Golf: Gibberish Echo

This is my first code golf challenge, as such I am not entirely certain if it is suitable as a Code Golf challenge, but it's all a learning experience. The challenge is that in as few characters as ...
-2
votes
2answers
158 views

Find Anagrams in the Dictionary [closed]

This a code challenge. The winner will be the person to provide the most efficient implementation of the solution in terms of algorithmic complexity. Using the dictionary found in '/usr/share/dict' ...
14
votes
17answers
2k views

Find the substring with the most 1's in a sequence

Introduction I want to find the substring with the most 1's in a sequence of 0's and 1's. Input Your program has two inputs, the sequence and the substring length. The sequence is any number of ...
11
votes
22answers
1k views

String to Binary

This is a code golf challenge. Just like the title says, write a program to covert a string of ascii characters into binary. For example: "Hello World!" should turn into 1001000 1100101 1101100 ...
6
votes
3answers
388 views

Retrograde morse (d)e(n)coder

This question is inspired by retrograde music. Retrograde music is a piece of music that can both be played normally (from the beginning to the end) as reversed (from the end the beginning). A similar ...
23
votes
9answers
2k views

Word Search Puzzle

Given a rectangular text as a word search puzzle and a search string, determine if the text contains the search string. The search string may appear: horizontally, vertically or diagonally forwards ...
45
votes
20answers
5k views

Significant Whitespace

We define whitespace to be any of the three characters, tab (0x09), newline (0x0A) or space (0x20). For this challenge, you're to write two programs or functions in the same programming language, ...
18
votes
9answers
1k views

Caesar-Cypher-Mania

The Caesar Cypher is a very simple substitution cypher where each letter is shifted by a fixed offset (looping around Z to A). Similarly, we can also a Caesar cypher for the set of printable ASCII ...
12
votes
4answers
574 views

Write a Magic Spellchecker

The game Waving Hands is somewhere between a pen-and-paper Magic: the Gathering and a very elaborate Rock Paper Scissors. Each turn you write down one of eight gestures for each hand: wiggled ...
2
votes
1answer
107 views

String generator based on a wildcard [duplicate]

Your task, if you accept it, is to make a string generator that generates strings based on a wildcard. You can make a function or a full program that receives 1 argument and sends to the standard ...
17
votes
30answers
2k views

Convert a string of binary characters to the ASCII equivalents

Take a string of binary characters separated by a space, and convert it to an ASCII string. For example... 1001000 1100101 1101100 1101100 1101111 100000 1010111 1101111 1110010 1101100 1100100 ...
35
votes
9answers
2k views

Reverse indentation

I've heard that your code can run faster if you indent it in reverse, so that the compiler can process it like a tree design pattern from the very top of the "branches" down. This helps because ...
6
votes
8answers
272 views

Finish a symmetrical map

You are given one-quarter of a map that is symmetrical over the x- and y-axes as input. The program should print the complete map. The map can contain the following characters: -+/\|., and they ...
10
votes
2answers
385 views

Concatenate Strings with Context

Strings with Context For the purposes of this challenge, a string with context is a triple of strings, called the left context, the data part, and the right context. It represents a substring of a ...
7
votes
2answers
313 views

Cyclically Equivalent Words

Cyclic Equivalence Let L be a list of pairs of letters, for example [(a,b), (a,c)]. We call L a list of commutators. Two words are cyclically equivalent over L, if one can be transformed into the ...
51
votes
77answers
9k views

Print the alphabet without using each vowel

Inspiration: in 1939, a man named Ernest Vincent Wright wrote a novel called Gadsby without using the letter 'e'. Your task is to write a set of (up to 5) programs in any language (which has a ...
11
votes
5answers
395 views

Generalized Gematria Calculator

Create a bidirectional Gematria calculator, for any given sequence of Unicode characters as the alphabet. Gematri-What? Gematria is a system of assigning numerical values to symbols, developed by ...
9
votes
15answers
2k views

Sum of strings without converting

You have to take 2 string inputs and output the sum of these two strings without converting them to int or using any numeric data type. ex. string one = "123"; string two = "456"; string sum = ...
38
votes
7answers
3k views

Avoiding Rivers

Background In typography, rivers are visual gaps in a block of text, which occur due to coincidental alignment of spaces. These are particularly annoying since your brain seems to pick them up more ...
19
votes
38answers
4k views

Answer to life, the universe, and everything

Post the shortest code possible that will output 42 only if the input is: abbcccddddeeeee ... zzzzzzzzzzzzzzzzzzzzzzzzzz
41
votes
2answers
3k views

Regex that only matches itself

There are some pretty cool challenges out there involving regex (Self-matching regex, Regex validating regex) This may well be impossible, but is there a regex that will ONLY match itself? NOTE, ...
8
votes
6answers
1k views

Interpret /// (pronounced 'slashes')

Because we can't get enough of esoteric language golfs, can we? ///—pronounced slashes—is a fun little language based on the s/// regex-replacement function of Perl fame. It contains only ...
1
vote
25answers
1k views

Count how many characters are in the program's source

Write a program that counts and prints the number of characters in it's own source code to standard output. The number must be generated from counting the characters. This Ruby solution would not be ...
35
votes
23answers
5k views

Draw the Sawtooth Alphabet

A simple one today. Write the shortest program that draws a "sawtooth alphabet" given a positive integer for the height. You must write the name of your programming language when you come to the ...
62
votes
93answers
16k views

Sing Happy Birthday to your favourite programming language

Your favourite programming language has just had a birthday. Be nice and sing the Happy Birthday song to him (or her, if you will). Of course you should accomplish this by writing a program in that ...
4
votes
4answers
496 views

Find imperfect anagrams

The goal of this challenge is to write a program which takes a string (of any length) as input and displays anagrams (see these examples of anagrams) of this string, made by taking words in a ...
7
votes
8answers
842 views

Practical Golf - US States [closed]

My family has an e-commerce business. On our own site, we force people to choose their state from a dropdown menu when they enter their address, but through some other channels we use, customers can ...
15
votes
36answers
1k views

Shortest program to split a string at non-digits without RegExps

EDIT: If you're using Lisp, I have given some guidelines at the bottom in counting bytes. Objective: Make the shortest function that splits a string at non-digits and returns an array consisting of ...
10
votes
24answers
2k views

Print a string with vertical words

Your task is to take an input string of ascii characters and output the string as a series of vertical words separated by spaces. An example is shown below: Given the string: Hello, World! My name ...
21
votes
32answers
3k views

Generating a single string with an Oxford comma from a list

What are some clever (brief and idiomatic) approaches to taking a list of strings and returning a single properly punctuated string built from the list, with each element quoted. This came up for me ...