Questions tagged [code-challenge]
A code challenge is a competition for creative ways to solve a programming puzzle with an objective winning criterion not covered by other scoring tags (e.g. code-golf).
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How Many Staircases [duplicate]
Problem
You're a staircase engineer on a house and realize you only have n rectangles to create a staircase. So you are tasked with finding the number of ways to ...
- 327
26
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39
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Repeat your program to print Fibonacci numbers
Write a program fragment so that, when repeated N times it prints the Nth Fibonacci number. For example, if your program is print(x) then:
...
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10
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12
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Encrypting Emojis
Problem
You are tasked with creating a program that performs emoji encryption on a given string of emojis. In this encryption scheme, each emoji is replaced by a unique character (from ...
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10
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How Turing complete is your language?
Find the maximum possible number of disjoint sets of characters, that are Turing complete subsets of your language.
Rules:
You can assume your Turing complete subset is contained in/called from a ...
- 4,781
8
votes
8
answers
602
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Magic OEIS formulae (Robbers' thread)
This is the robbers' thread. See the cops' thread here.
In this cops and robbers challenge, the cops will be tasked with writing an algorithm that computes some function of their choice, while the ...
- 22.2k
12
votes
9
answers
700
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Magic OEIS formulae (Cops' thread)
This is the cops' thread. See the robbers' thread here.
In this cops and robbers challenge, the cops will be tasked with writing an algorithm that computes some function of their choice, while the ...
- 22.2k
1
vote
1
answer
176
views
Most elegant one-liner to generate sqlite INSERTs
Challenge
You find yourself in a bash terminal, and want to do some simple tests
on sqlite3.
So you issue the following command:
...
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1
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0
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making a binary string palindrome using xor operations [closed]
Problem
You are given a binary string A of length N.
You can perform the following type of operation on the string A:
Choose two different indices \$i\$ and \$j\$ (\$1 \le i\$, \$j \le N\$)
Change \$...
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3
votes
4
answers
991
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Write the smallest possible code in x86-64 to implement the "<=>" operator
Languages, such as C++, have introduced a new comparison operator: <=>.
This operator returns -1, 0, or 1† when comparing two items together:
−1 means the ...
- 189
19
votes
17
answers
2k
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Approximate my atomic weight
Each element on the periodic table of the elements has an atomic weight. For example, boron (element 5) has an atomic weight of 10.81. Your challenge is to write a program which takes as input the ...
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12
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3
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><> numbers metagolf
I struggle to easily encode big numbers in ><>. If only there was a program that could find the best way for me?
What is ><>
...
- 11.4k
25
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54
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Range of ASCII values
Your task
Given a string, output the range of ASCII values.
Example
Let's say we have the string Hello.
We get the ASCII values:
...
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39
votes
5
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50 digits of π in HQ0-9+-INCOMPUTABLE?
Background
HQ0-9+-INCOMPUTABLE?! is a half-joke programming language introduced in Internet Problem Solving Contest 2011, Problem H.
HQ9+ is an esoteric programming language specialized for certain
...
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3
votes
4
answers
871
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A multidimensional strategy challenge
The wizard is determined to pose the most challenging challenge yet for which he believes the previous solution techniques will not work. He decides to go multidimensional.
If there is a number line ...
user108721
17
votes
11
answers
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Numbers vs. Strings: Language fitness challenge
inspired by thejonymyster's idea
Rules
This challenge is about finding languages that are very suitable for one task but quite the opposite in the other. The two tasks share a theme, but Task 1 is ...
- 73.2k
8
votes
0
answers
392
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Turing Machine that outputs pi
Turing Machine Preliminaries
A Turing machine is specified by the following data
A finite set of symbols S = \$\{s_1,s_2,...\}\$
A finite set of states M = \$\{m_1,m_2,...\}\$
A partially defined ...
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25
votes
11
answers
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Write a program with the smallest width
Print or return the following text:
Hello world! The quick brown fox jumps over a lazy dog.
However, your submission will not be scored in bytes. Instead, ...
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5
votes
4
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Strategy: The cunning cousin witch
The wizard has a cunning cousin who is a witch. She looks down on the wizard, regarding him and his puzzles as mathematically naive. On reading his latest puzzle, she scorned him for always asking ...
user108721
5
votes
2
answers
917
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Optimal strategy to defeat the wizard
In this game, you can look inside one box at a time chosen by you. When you do that, you can see how many coins there are in that box.
The wizard has one last twist for you. At any point, you can ...
user108721
20
votes
12
answers
3k
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Optimal strategy for wandering robots
If the agent is at the origin it always moves right when you choose it.
The goal is to get one agent to 10.
The cost is the sum of the square of the total number of moves (left or right) taken by each ...
user108721
6
votes
2
answers
287
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Case Conversion Polyglot
Your task is to write a program that performs case conversion from plain text, and other case formats, into one of the specified formats below. Inputs will be either plain lowercase text, or one of ...
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5
votes
7
answers
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Typo resistant pin codes [closed]
Background
I was working on a system where for convenience (not security) people could use four digit codes to identify themselves. I figured this is something that may actually be useful in many real ...
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5
votes
0
answers
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Find the best character arrangement
You want to write your English essay. However, all characters on your keyboard broke other than the arrow keys and the enter key. You want to find out how to place the characters so you can write your ...
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19
votes
11
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Write a near crystalline program
A pristine program is a program that does not have any errors itself but will error if you modify it by removing any contiguous substring other than the entire program.
A crystalline program is sort ...
- 95.5k
1
vote
1
answer
252
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Implement the slowest possible sorting algorithm that retains a fast best case [closed]
I have recently been on a quest to create really really slow sorting algorithms that make Bogosort seem like it is the best.
The task is simple: Sort an array of integers in as long average time as ...
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-12
votes
5
answers
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12 with no 1234567890, but polyglot
This is my 12th question, so I thought of this idea.
Goal:
Output 12, with any preceding or trailing whitespace permitted
In as many languages as possible (where different versions or flags count as ...
- 1,532
29
votes
21
answers
4k
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Add a hidden language to a polyglot
Inspired/mostly copied but I don't think it's a dupe. Also Inspired.
In this challenge, you will create polyglots that include all languages from previous answers, and another language which you won't ...
- 34.5k
6
votes
1
answer
658
views
Irradiated Polyglots
Design a function or program that, when run normally, outputs the triangular numbers. However, when any single character is deleted, the program/function should not function in the original ...
- 1,357
5
votes
1
answer
184
views
BitCycle Metagolf
Background
BitCycle is a two-dimensional Turing-complete programming language involves moving bits around a playfield.
Because I am too lazy to write BitCycle programs myself, you will be writing a ...
- 12.3k
27
votes
28
answers
4k
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What's the Missing Code? (Cops)
Cops' Challenge
Robbers' challenge here.
It has now been four days since the challenge was posted so all new answers should be marked as non-competing in the title. These answers can still be cracked ...
- 1,155
3
votes
0
answers
185
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Calculate the probability of getting this hand in n tries [closed]
Imagine there is a card game where the primary objective of the game is to get 4 of one card in your hand.
Game mechanics
Each player starts of with 10 cards in their hand. The remaining 32 cards (...
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4
votes
3
answers
275
views
Find All Digitroot Cyclic Sequences With Length Greater Than One
Digital sum, DR, Digit root is the iterative process of summing digits of a number until you end up with a single digit root number: e.g. digit root of 12345 is 6 since 1 + 2 + 3 + 4 + 5 = 15 = 1+5. ...
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3
votes
2
answers
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views
Implement constant-latency branchless multiplication efficiently
Modern hardware can perform multiplication very fast in a constant latency of 3~4 cycles. But some tiny chips for embedded environments sometimes lack hardware multiplication, which has to be emulated ...
- 2,325
9
votes
3
answers
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Build an optimizing Brainfuck compiler/interpreter
the goal
Build an optimizing Brainfuck implementation. Whether it is a compiler, an interpreter, a JIT compiler, or whatever else is up to you.
scoring
A reference implementation (...
- 2,325
6
votes
3
answers
297
views
Write a regex that would increment a 2-digit hexadecimal number
Your regex will receive a string of the form
!XX!
#<extra>
where X is any hexadecimal digit (0-9 and A-F capital letters ...
- 71
13
votes
1
answer
572
views
Longest infinite loop in 5 states
Challenge Statement
The goal of this challenge is to build the 5 state Infinite Time Turing Machine that takes the longest to halt. Since Infinite Time Turing Machines can run for infinite time your ...
- 95.5k
0
votes
0
answers
214
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Infinite-Time Busy Beaver
An infinite time Turing machine is a generalization of a Turing machine to infinite computation lengths. It has three tapes: two of them are blank initially, and the other one contains the input to ...
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6
votes
2
answers
286
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Generate Matching Regexes
Write a program that takes two lists of strings and generates a javascript regex that fully matches all the strings in the first list and matches none of the strings in the second list.
To be specific ...
- 1,161
10
votes
8
answers
602
views
Biggest katlani noun dictionary in 400 bytes
Katlani is a constructed language being designed in chat. In this challenge, your goal is to print the largest dictionary of katlani nouns possible in 400 bytes or less.
Task
In 400 bytes or less, ...
- 18.5k
8
votes
8
answers
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views
From code to golf (Robbers' thread)
This is a cops-and-robbers challenge, the cops' thread is here
You can change the word code into golf by changing a letter at a ...
- 34.5k
12
votes
10
answers
851
views
From code to golf (Cops' thread)
This is a cops-and-robbers challenge, the robbers' thread is here
You can change the word code into golf by changing a letter at ...
- 34.5k
6
votes
1
answer
202
views
Represent any integer with an expression that uses no digit besides '4' [closed]
Fourward (Introduction)
I have an unhealthy obsession with the number 4. I love it so much, in fact, that seeing any other digit is frustrating to me. I therefour wish to create a 'Fourier ...
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-2
votes
1
answer
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Program compressor
Choose a language and write a program in the language that:
Take a valid program of the language as input,
Output a string(bytearray, etc.). It needn't be a valid program.
Only finite valid inputs ...
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20
votes
6
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Wordle solver challenge
Wordle is a daily online word game that has received considerable attention recently.
The Game
The object is to guess a secret word in the fewest attempts. Consider the following instance of the game:
...
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-7
votes
2
answers
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Multiplying numbers [duplicate]
Your task, is simply to multiply 2 integers given in input, separated by a ",". The catch is, you cannot use the multiplication operator "*", even if it is being used differently, ...
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23
votes
6
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Play the Fruit Box Game
Play the Fruit Box Game
Intro
Fruit Box is a game consisting of a 10x17 grid of numbers, each between 1 and 9, where the goal is to clear as many numbers as possible in a two-minute time window. In ...
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18
votes
1
answer
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Largest SKI output in less than 200 combinators
The Challenge
Create an terminating expression in SKI Combinator Calculus in less than 200 combinators (S, K, I) that reduces to the expression with the most combinators.
There will be no limit on how ...
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votes
20
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Kolmogorov-simple numbers
If you visit Code Golf often, you may have heard of Kolmogorov complexity. It's usually defined as the amount of bytes required to express some string in a programming language.
Here the Kolmogorov-...
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-1
votes
1
answer
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Draw Lines in ASCII [closed]
Challenge
Draw lines in ASCII corresponding to given inputs:
in the first line there are given size of rows and columns of the view and number of separators between each point
in the second line is ...
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votes
11
answers
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Infinite ordinals from a well-ordering
Your task is to write a short program that represents a large (infinite) ordinal, using a well-ordering of the set of positive integers. Your program will take two different positive integers and ...
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