Questions tagged [source-layout]
For challenges that involve the physical layout or physical manipulation of source-code.
191 questions
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Hyperprogramming: N+N, N×N, N^N all in one
Write a program that takes in a number N from 1 to 9 inclusive. In its native form your program should output N+N. E.g. output 2 if N is ...
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Hello, World! (Every other character)
Write a program that prints "Hello, World!".
But also, if you take only the first, third, fifth, etc. characters of your program, the resulting program should still print "Hello, World!".
If your ...
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Write a program that always outputs "2012" - even if it's modified!
This idea is not mine, though I don't know where it originated. I once met it in a programming contest very long ago (1998, if I remember correctly). The task is to write a program in your favorite ...
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What are the five most powerful characters in your language?
Choose any five characters your language supports. There are 5! = 5×4×3×2×1 = 120 ways these can be arranged into a 5-character string that contains each character once; 120 permutations.
Choose your ...
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votes
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Print a Negative of your Code
Consider a square of printable ASCII characters (code points 0x20 to 0x7E) for side length N, like the following (here, N = 6):
...
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From Programming Puzzles to Code Golf
Your task is to write a program that outputs the exact string Programming Puzzles (trailing newline optional), but when all spaces, tabs, and newlines are removed ...
user58826
87
votes
20
answers
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Fault-Tolerant Hello World
At the end of your interview, the Evil Interviewer tells you, "We make all of our applicants take a short coding test, to see if they really know what they are talking about. Don't worry; it's ...
user7486
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votes
16
answers
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Error 404: Character Not Found
Scenario
One of your friends is struggling on a homework assignment. He needs a simple program which prints the first 404 natural numbers:
...
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69
votes
6
answers
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Powerprogramming: O(1^N), O(N^1), O(2^N), O(N^2) all in one
Write a program (or function) that exhibits four common big O time complexities depending on how it is run. In any form it takes in a positive integer N which you may assume is less than 231.
When the ...
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68
votes
36
answers
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Write a Rectangular Program that Outputs the Number of Times it was Rotated
The title says it all. Your goal is to write a program that forms a w×h rectangle of characters that can be rotated and re-run to output the number of 90° Counter-Clockwise (CCW) rotations that have ...
- 90.8k
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votes
44
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Factorial in haiku!
Task
Create a program that calculates the factorial of a number using no built-in factorial functions. Easy? The catch is that you must write your entire program (including testing it) in haiku form.
...
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58
votes
72
answers
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I reverse the source code, you negate the output!
Your task, if you wish to accept it, is to write a program that outputs a non-zero number(can be integer or float). The tricky part is that if I reverse your source code, the output must be the ...
- 4,026
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votes
26
answers
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DON'T... do NOT lowercase UPPERCASE this!
Write a program that outputs its input unchanged. However:
If all uppercase characters are removed from the program, it lowercases all uppercase letters.
If all lowercase characters are removed from ...
- 7,937
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votes
24
answers
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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, ...
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51
votes
51
answers
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Third time the charm
Your task, if you wish to accept it, is to write a program that outputs a positive integer (higher than 0). If the source code is duplicated the output must remain the same. The tricky part is that if ...
- 1,045
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votes
24
answers
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A Chiral Puzzle
A shape is chiral if no amount of rotation can make it look like it's mirror image. In this puzzle we will be writing chiral computer programs.
For this puzzle we will think of a program as a ...
- 103k
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votes
16
answers
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Sierpinskified Code
Write a rectangular block of text that when arranged into a Sierpinski carpet, using same-sized blocks of spaces for the empty portions, creates a program that outputs the iteration number of the ...
- 90.8k
48
votes
3
answers
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Coding Around The Clock
Write a single line program two or more characters long that contains no line terminators and takes no input. For example, your program might be:
MyProgram
When ...
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48
votes
3
answers
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Code that runs the Game of Life on itself
Write two rectangular blocks of code, each w characters wide and h characters tall, that implement Conway's Game of Life when arranged in a grid. (w and h may be any positive integers)
For example, ...
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47
votes
14
answers
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Make a code square with your favorite word [closed]
Pick your favorite 6 letter common English word that has no repeated letters, such as wombat.
Write a program in an N×N grid of characters without comments such ...
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votes
20
answers
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Create a square of increasing size by replicating the initial code
Your assignment is to write a program of even length, that prints an ASCII-art square (described below), that increases its side length by 1 unit each time the original source code is pasted in the ...
user77954
44
votes
69
answers
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I reverse the source code, you negate the input!
Blatant rip-off of a rip-off. Go upvote those!
Your task, if you wish to accept it, is to write a program/function that outputs/returns its integer input/argument. The tricky part is that if I ...
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Code close to the challenge: Sum of integers
This is a simple challenge:
Given a sequence of integers, find the sum of all integers in it.
But with a twist.
Your score is the Levenshtein distance between your code and the following phrase (The ...
user40734
43
votes
8
answers
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40 Numbers in 9 Bytes
There are 40 ways a directed Hamiltonian path can be arranged on a 3×3 grid:
This graphic (thanks Sp3000!) shows only the 20 undirected paths. Traverse each colored line in both directions for the 40 ...
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42
votes
19
answers
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Program template for printing *any* string
Write a program with the following properties:
When run as-is, the program produces no output (i.e. 0 bytes of output).
There is a location within the program (of your choice: it could be at the start,...
user62131
41
votes
9
answers
5k
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Shifting-Oriented Programming
A string can be shifted by a number n by getting the byte value c of each character in the string, calculating ...
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41
votes
25
answers
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Hide the Needle in the Haystack (Cops)
This is part of a cops-and-robbers challenge. Go here for the robbers' part.
The Cops' Challenge
You should write a program or function in a language of your choice, which outputs the string ...
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votes
13
answers
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A well linked challenge
An activity I sometimes do when I'm bored is to write a couple of characters in matching pairs. I then draw lines (over the tops never below) to connect these characters. For example I might write \$...
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votes
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Concatenated halting problem: no + no + ... = yes
Challenge
Write \$2 \le n \le 10\$ distinct, valid non-halting full programs in your language of choice. If all of them are concatenated in order, the resulting full program should be a valid halting ...
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40
votes
29
answers
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Double-time is not double time
Based on this challenge.
In the rhythm game osu!, the difficulty modifier "Double-time" actually only increases the speed by 50%.
Your task, is to write a program that outputs a positive ...
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votes
31
answers
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Cat, Quine, Hello World
Write a cat program, a quine, and a Hello World in the same language such that when two specific programs of the three are concatenated in a certain order, you get the third program. It does not ...
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Prime Up your code
Input
no input for this challenge
The Challenge
Write a code that outputs:
The first 10 prime numbers whose sum of their digits equal the number of bytes of your code
Examples
Let's say your code is <...
user73398
39
votes
14
answers
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Make a Geiger Counter
A Geiger counter is a device that is used to detect radiation.
We will be making a Geiger counter program.
As we all know, when radiation hits a computer program it removes exactly 1 byte at random. ...
- 103k
38
votes
25
answers
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I transpose the source code, you transpose the input!
Rip-off of a rip-off of a rip-off of a rip-off. Go upvote those!
Your task, if you wish to accept it, is to write a program/function that outputs/returns its input/argument¹. The tricky part is that ...
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37
votes
28
answers
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Is the matrix centrosymmetric... and so is the code?
Defintion
A centrosymmetric matrix is a square matrix that is symmetric about its center. More rigorously, a matrix \$A\$ of size \$n \times n\$ is centrosymmetric if, for any \$i,\: j \in ([1, n] \...
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Letter, Number, Symbol, Space, Repeat
There are 97 ASCII characters that people encounter on a regular basis. They fall into four categories:
Letters (52 total)
...
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35
votes
17
answers
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Hidden Inversions (Cops' Thread)
This is a cops-and-robbers puzzle the robbers' thread can be found here.
Your task will be two write two programs (or functions) such that they are anagrams of each other and one performs the left ...
- 103k
35
votes
4
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Make The Finest Magic Code Square
In math a magic square is an N×N grid of numbers from 1 to N2 such that every row, column, and diagonal sums to the same total. For example here's a 3×3 magic square:
In this challenge we'...
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21
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Longest Non-Repeating Substring
Given a string as input find the longest contiguous substring that does not have any character twice or more. If there are multiple such substrings you may output either. You may assume that the ...
- 103k
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votes
3
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Programming Tetris Blocks (Literally)
In the game Tetris, there are 7 types of bricks or Tetriminoes, which are mathematically known as tetrominoes because they are all made with 4 square segments:
The have the names I, J, L, O, S, T, and ...
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22
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Pass on your radiation
The task here is pretty simple. You should write a program that takes a string as input and outputs it (that is a cat program).
Additionally when the \$n\$th byte of your program is removed (without ...
- 103k
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votes
18
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Jumblers vs Rebuilders: Coding with Tetris Bricks
In traditional Tetris, there are 7 distinct tetromino bricks, each denoted by a letter similar to its shape.
...
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One hundred passwords
I have one hundred vaults, each one within another. Each vault has a password, consisting of a single number.
95 43 81 89 56 89 57 67 7 45 34 34 78 88 14 40 81 23 26 78 46 8 ...
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Count how many times your program repeats
Your task is to write a program or function. Its output/return value must follow these rules:
The program outputs 1
The program repeated ...
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33
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29
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Double it your way
There have been a couple of challenges involving doubling source code: here and here. The task we have here is a bit harder, but should be doable in almost every language.
In this challenge, you will ...
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17
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2 Cats in a Quine
Challenge
Make two programs, A and B, which are both cat programs in the same language. When concatenated, AB (also in the same language) should be a quine.
For example, suppose ...
- 10k
33
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11
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Multiplication by Self-Modification
...at least for some definition of "self-modification".
The Task
In this challenge, your task is to write three strings A, B ...
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32
votes
57
answers
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Internal Truth Machine
It's a normal truth machine but instead of taking input, it uses the first character of the program. Thus, internal.
The 0 and 1 are plain characters, i.e. ASCII code 0x30 and 0x31 respectively.
...
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Inverse function
Wouldn't it be neat if programming functions could be inverted, just like the mathematical function they implement?
Write a function (or program) that takes one input ...
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30
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Join N copies of a snippet to produce N^2 characters
Challenge
Write the shortest snippet of code possible such that, when N copies of it are concatenated together, the number of characters output is N2. N will be a positive integer.
For example if the ...
- 90.8k