Questions tagged [restricted-source]
Imposes a restriction on the source code used to solve the challenge, for example, having no numbers in the source code.
145
questions
129
votes
64answers
18k views
Fewest (distinct) characters for Turing Completeness
Summary:
For any given language, what is the smallest amount of unique characters for your language to be Turing-Complete?
Challenge:
For any language of your choice, find the smallest subset of ...
122
votes
74answers
26k views
Largest Number Printable
Your goal is to write a program that prints a number. The bigger the number, the more points you'll get. But be careful! Code length is both limited and heavily weighted in the scoring function. Your ...
129
votes
131answers
40k 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 ...
600
votes
300answers
223k views
Produce the number 2014 without any numbers in your source code
Note to challenge writers as per meta consensus:
This question was well-received when it was posted, but challenges
like this, asking answerers to Do X without using
Y
are likely to be poorly received....
91
votes
23answers
11k views
Programming a Pristine World
Let's define a pristine program as a program that does not have any errors itself but will error if you modify it by removing any contiguous substring of \$N\$ characters, where \$1 \le N < \text{...
40
votes
9answers
5k views
“Convenient palindrome” checker
If you've ever tried to write palindromic code before, you'd know how much brackets tend to get in your way. ()() is not a palindrome, even though it kinda looks ...
120
votes
95answers
22k views
ASCII's 95 Characters…95 Movie Quotes
Update: The winner has been decided, but the challenge is not over!
Finally, nearly 3 months after the question first started, someone has remained the last answerer for more than a week! ...
31
votes
45answers
6k views
Implement hyperexponentiation/tetration without the use of '^'
The Challenge
Implement tetration (aka Power Tower or Hyperexponentiation) with the least amount of characters.
The Conditions
Don't use the 'power' operator or its equivalents (such as ...
240
votes
121answers
34k views
Without using numbers, get the highest salary you can. But don't exaggerate!
As I'm applying for some jobs whose job advert doesn't state the salary, I imagined a particularly evil interviewer that would give the candidate the possibility to decide their own salary ...by "...
167
votes
67answers
23k views
How high can you count?
Challenge:
Your task is to write as many programs / functions / snippets as you can, where each one outputs / prints / returns an integer. The first program must output the integer ...
94
votes
52answers
9k views
Find an Illegal String
The challenge is to find a string of characters that cannot appear in any legal program in your programming language of choice. That includes comments, strings, or other "non-executable" parts.
...
38
votes
16answers
5k views
Tips for restricted source in Python
Just like code-golf, restricted-source pushes one to exploit quirks and hidden features of the Python language. We already have a place to collect all these tips for code-golf, those for restricted-...
65
votes
20answers
7k views
Just repeat yourself
Write a program that outputs
Do not repeat yourself!
Your program code must respect the following constraints :
its length must be an even number
each ...
31
votes
16answers
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 ...
23
votes
25answers
8k views
Look and say sequence [duplicate]
The look and say sequence is a basic form of run length encoding.
The sequence starts with the number 1 and each additional number encodes the number of digits that are repeated before each digit ...
4
votes
31answers
986 views
Hello ASCII World!
Construct a full program which outputs Hello, World!. The score of your submission will be equal to the sum of all of the ASCII values of the distinct characters. ...
62
votes
109answers
11k views
Print X without X (cop's thread)
This is the cop's thread of a cops-and-robbers challenge. You can view the robber's thread here
A pretty common beginner style question is to print some string, but there's a catch! You need to do it ...
77
votes
190answers
20k views
The Letter A without A
Your task is to display the letter "A" alone, without anything else, except any form of trailing newlines if you cannot avoid them, doing so in a program and/or snippet. Code that returns (instead of ...
52
votes
50answers
8k views
Print all ASCII alphanumeric characters without using them
Challenge
Print the following characters:
abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890
The catch is that you may not use any one of them in ...
71
votes
81answers
6k views
No strings (or numbers) attached
If you like this, consider participating in:
The Official Dyalog APL 2016 Year Game
The monthly Dyalog APL 2017 Code Golf Challenge
Make 12 snippets/expressions, in the same language, that result in ...
66
votes
11answers
3k views
Only Even Bytes
The scenario
Lately you have been noticing some strange behavior with your favorite text editor. At first it seemed that it was ignoring random characters in your code when writing to disk. After a ...
17
votes
10answers
2k views
The Symbols vs. The Letters
The Symbols vs. The Letters
The ASCII characters have been divided once again! Your sets are The Letters and The Symbols.
The Letters
...
60
votes
161answers
8k views
Output your Score!
Challenge:
The concept is simple enough: write a full program to output its own code golf score!
Output should only be the byte count of your program and a trailing ...
42
votes
16answers
8k views
What's the shortest contiguous subset of ASCII you need to output the rest?
The printable ASCII characters (hex codes 20 to 7E) in order are:
...
8
votes
17answers
3k views
Multiply without multiply [closed]
Write the fastest (best big-O) and smallest multiplication algorithm for positive integers, without using multiplication operators. You are only allowed addition, subtraction, logical functions (AND, ...
30
votes
16answers
6k views
Multiply two numbers without using any numbers
You are given as input two strings representing positive integers in base 10, such as "12345" and "42". Your task is to output a ...
23
votes
30answers
2k views
Palindromic palindrome generator
Create a program, that converts input string to a palindrome starting with the input string. The program itself must be a palindrome.
For example input: neverod, ...
20
votes
21answers
2k views
Length of String Using Set Theory
From Wikipedia Set-theoretic definition of natural numbers
The set N of natural numbers is defined as the smallest set containing
0 and closed under the successor function S defined by S(n) = n ∪ ...
225
votes
25answers
23k views
DISARM THE B.O.M.B.!
You have been hired for your tech knowledge as a Secret Agent's sidekick to ensure that the good guy can get his job done and the world can be saved.
This is your last mission before retiring with a ...
111
votes
69answers
27k views
I'm a palindrome. Are you?
There have been a couple of previous attempts to ask this question, but neither conforms to modern standards on this site. Per discussion on Meta, I'm reposting it in a way that allows for fair ...
80
votes
102answers
13k views
Hello World 0.0!
source: Dilbert, September 8, 1992
I'm hoping to add a new twist on the classic "Hello World!" program.
Code a program that outputs Hello World! without:
String/...
48
votes
2answers
2k views
JSF**k with only 5 symbols?
This is not a challenge but a question, I figured it was on topic because of
Non-challenge questions that are related to solving programming puzzles or a particular type of challenge are also on ...
76
votes
37answers
12k views
Non-discriminating Programming
We say a string is non-discriminating if each of the string's characters appears the same number of times and at least twice.
Examples
"aa!1 1 !a !1" is non-...
45
votes
1answer
1k views
Cyclic Levenquine
Background
As most PPCG regulars will know, a quine is a program which outputs its own source code when run; and the Levenshtein distance between two strings is the minimum number of insertions, ...
79
votes
71answers
16k views
Hello world! with limited character repetition
In a language of your choice, write a program that exactly outputs the characters Hello world! followed by a newline. The code:
should not use any character more ...
29
votes
69answers
9k views
Check whether an integer is a power of 2 without using +,- operations [closed]
Write a program that checks if the integer is a power of 2.
Sample input:
8
Sample output:
Yes
Sample input:
...
34
votes
97answers
9k views
Print X without X (robber's thread)
This is the robber's thread of a cops-and-robbers challenge. You can view the cop's thread here
A pretty common beginner style question is to print some string, but, there's a catch!, you need to do ...
35
votes
57answers
6k views
Capitalize first letter of each word of input
This is a relatively quick one, but I'm sure you'll like it.
Codegolf a program that will take input in the form of a sentence and then provide the output with the first letter capitalized in each ...
55
votes
24answers
6k 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, ...
54
votes
15answers
4k views
Write the whole of the holed using the unholed
The ASCII characters from decimal code 33 to 126 are:
!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~
...
33
votes
5answers
2k views
Left Hand vs. Right Hand — Typists Challenge
Your task is to pit each side of the keyboard against each other and build two programs, in the same language, one using only keys on the left-hand side of a standard keyboard that outputs ...
26
votes
11answers
2k views
Official Dyalog APL 2016 Year Game
If you think this could be fun, but too much work, consider participating in this much smaller challenge.
A bit of fun (and possibly frustration!) for 2016... Dyalog's "puzzle of the year". ...
21
votes
4answers
3k views
JSFuck Golf - Hello World
JSFuck is an esoteric language in which any Javascript statement can be accurately reproduced into another valid Javascript program that uses only the 6 characters ...
28
votes
18answers
6k views
Shortest Sorted Hello World
Write a program that takes no input and prints Hello, World! to stdout or your language's closest alternative. The catch is that each line in your program must only ...
13
votes
9answers
2k views
Print the first 128 prime numbers without using any reserved words
The obvious solution would be to just print them as a string, but is it possible to write a shorter code?
Requirements:
No input should be processed, and the output should be in the form of ...
5
votes
49answers
9k views
Find the absolute value of a number without built-in functions [closed]
The challenge is to take any real number as input and output or return the absolute value. You may not use any built-in functions other than those dealing with input and output/returning. This is code ...
4
votes
28answers
1k views
Implement an integer parser
Implement an integer parser in the shortest code possible, with the following restrictions:
The function or program can only take one argument: a string (or equivalent). Assume it to be signed and ...
-7
votes
28answers
1k views
Produce the word 'codegolf' without using any of its characters in code [closed]
You need to produce the word codegolf
Rules:
None of the characters of the word codegolf (i.e. 'c', 'o', 'd', 'e', 'g', 'o', 'l' and 'f') in either case can ...
2
votes
8answers
423 views
Exponentiation of natural numbers using only primitive integer operations [duplicate]
The challenge
Implement the C equivalent of the pow() function (exponentiation) for natural numbers, in a language of your choosing, using only addition, ...
85
votes
132answers
48k views
Loop without 'looping' [closed]
A question similar to this has been asked a couple of years ago, but this one is even trickier.
The challenge is simple. Write a program (in your language of choice) that repeatedly executes code ...
