Questions tagged [cops-and-robbers]
For challenges which consist of two adversary (and asymmetric) sub-challenges.
155
questions
2
votes
1
answer
201
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Hashers and Crashers (Robbers)
This is the robbers thread of this cops and robbers challenge. The cops thread is here.
Related, but hashes numbers instead of strings and uses a different scoring system.
Definitions
A hash collision ...
6
votes
1
answer
232
views
Hashers and Crashers (Cops)
This is the cops thread of this cops and robbers challenge. The robbers thread is here.
Related, but hashes numbers instead of strings and uses a different scoring system.
Definitions
A hash collision ...
8
votes
8
answers
619
views
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 ...
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12
votes
9
answers
725
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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 ...
- 22.3k
11
votes
11
answers
1k
views
(Robbers) Fast and Golfiest Season 1: The Lord of the Strings
Fast and Golfiest Robbers Thread
Welcome to the first season of Fast and Golfiest, a cops-and-robbers challenge! I designed this challenge to encourage competitive coding for efficiency (fastest ...
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17
votes
15
answers
1k
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(Cops) Fast and Golfiest Season 1: The Lord of the Strings
Fast and Golfiest Cops Thread
Welcome to the first season of Fast and Golfiest, a cops-and-robbers challenge! I designed this challenge to encourage competitive coding for efficiency (fastest ...
- 590
9
votes
9
answers
2k
views
Polyglot Quiz (Robbers' thread)
This is the robbers' thread. For the main rules to this challenge see the cops' thread
In this challenge, robbers will choose a cop's vulnerable or safe post and try to figure out a pair of languages ...
- 96.5k
21
votes
15
answers
2k
views
Polyglot Quiz (Cops' thread)
This is the cops' thread of a cops-and-robbers challenge. The robbers' thread can be found here
In this challenge as a cop you will choose two programming languages A and B, as well as a non-empty ...
- 96.5k
9
votes
10
answers
628
views
Two In One: Guess That Language - Robbers
Cops' challenge
This cops-and-robbers challenge challenges the Cop to write a non-empty program that, when run, produces some non-empty output in language A, and, when reversed, produces some non-...
- 1,530
19
votes
15
answers
2k
views
Two In One: Guess That Language - Cops
Robber's challenge
This cops-and-robbers challenge challenges the Cop to write a non-empty program that, when run, produces some non-empty output in language A, and, when reversed, produces some non-...
- 1,530
29
votes
21
answers
4k
views
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 ...
- 35.6k
10
votes
13
answers
3k
views
Robbers: Smallest subset of characters required for Turing Completeness
This is the robbers' challenge. The cops' one is here.
In Fewest (distinct) characters for Turing Completeness, the goal is to find the minimum number of characters which make a language Turing ...
- 18.6k
29
votes
31
answers
7k
views
Smallest subset of characters required for Turing Completeness
In Fewest (distinct) characters for Turing Completeness, the goal is to find the minimum number of characters which make a language Turing Complete...in other words, allow it to do any computation ...
- 18.6k
11
votes
19
answers
3k
views
What's the Missing Code? (Robbers)
Robbers' Challenge
Read the cops' challenge first.
In this cops-and-robbers challenge, you (the robbers) must find the correct string of characters, which, when added into the cop's code, will make it ...
- 1,155
27
votes
28
answers
4k
views
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
128
views
Hello Shue! (Robbers)
Cops thread (read first)
Robbers, your task is to find a Shue program p that when given the cops input i, outputs a program <...
- 7,828
4
votes
2
answers
336
views
Hello Shue! (Cops)
Robbers thread
In this cops-and-robbers challenge, your task is to write a program h that outputs "Hello Shue!". Next, you have to choose a string ...
- 7,828
7
votes
12
answers
821
views
Slice the source code (Robbers)
Cops thread
Robbers
Robbers, your job is to find the slices of the corresponding cop's code.
Scoring
The robber with the most cracks wins.
Example
Take this code:
...
- 3,443
9
votes
13
answers
1k
views
Slice the source code (Cops)
Robbers thread
Cops
Understanding slicing
Remember, slices are zero-indexed. Take this slice: [2:]. If the string is "abcde", the result is "cde" because the slice basically means &...
- 3,443
12
votes
11
answers
2k
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Output two numbers (Robbers' thread)
This is the robbers' thread to a cops-and-robbers challenge. Click the link to find the cops' thread.
In the cops' thread of this challenge, answerers will be writing programs which output two ...
- 96.5k
23
votes
20
answers
2k
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Output two numbers (Cops' thread)
This is the cops' thread to a cops-and-robbers challenge. Click the link to find the robbers' thread.
The challenge here is very simple. Create two programs of the same size, in the same language, ...
- 96.5k
7
votes
5
answers
449
views
Inject arbitrary code into a compiler (robbers)
This is the robbers' challenge. To post a cop, go here.
In this challenge, cops will invent a (likely simple) programming language, and write an interpreter, transpiler, or compiler that allows you to ...
- 18.6k
15
votes
9
answers
904
views
Inject arbitrary code into a compiler (cops)
This is the cops' challenge. To post a robber, go here.
In this challenge, cops will invent a (likely simple) programming language, and write an interpreter, transpiler, or compiler that allows you to ...
- 18.6k
8
votes
8
answers
470
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 ...
- 35.6k
12
votes
10
answers
880
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 ...
- 35.6k
7
votes
9
answers
355
views
Find my other token (Robbers)
Cops thread
Robbers,
Write a program in the cop's language using the cop's P string and your own S string, and the amount of each of them specified in the cop's post. Your S string may not exceed the ...
- 3,317
12
votes
12
answers
856
views
Find my other token (Cops)
Robbers thread
Cops,
Choose two strings of code, one public and one secret. We will call them P and S. You will be writing a program using only repetitions of these strings.
For example: if you choose ...
- 3,317
10
votes
44
answers
3k
views
Which character to change (Robbers)
Cops thread
Robbers, your task is to crack a cops answer. Reveal the character that should be changed and what it should be changed to too.
Please notify the cop if you cracked their challenge.
The ...
- 8,463
20
votes
49
answers
3k
views
Which character to change (Cops)
Robbers Thread
Cops, your task is to chose a program that prints a string (you can choose).
Although, if you change 1 character in your code, it should print another string.
But there's a twist: You ...
- 8,463
15
votes
18
answers
3k
views
It almost works (Robbers' Thread)
Cops' Thread
Your challenge is to find an uncracked, unsafe cop on the cops thread, and find an input value for which their code does not do as specified by the challenge.
You must use values within ...
- 35.6k
27
votes
21
answers
5k
views
It almost works (Cops' Thread)
Robbers' Thread
Your challenge is to find an existing challenge, and implement it in a way such that certain inputs fail. At least one input must not produce the correct output (use the other ...
- 35.6k
4
votes
2
answers
417
views
Hide a message in an image - Robbers
Choose a challenge from the Cops thread, determine the third hidden message, and describe how the system works.
Keep in mind limitations and possibilities available to Cops:
You are not expected to ...
- 9,891
11
votes
9
answers
886
views
Hide a message in an image - Cops
Robbers thread
Your task is to create a method for hiding information in an image. You will post three encoded messages of your choice (keep them classy), each with its associated image. Reveal the ...
- 9,891
8
votes
1
answer
376
views
I'm Jelly of Python (Robbers)
What does "jelly" mean in the title?. Cop's thread
Robbers, you are to choose an uncracked Cop answer, and attempt to find a Jelly program which is:
shorter than the Cop's answer
solves the ...
- 49.4k
12
votes
3
answers
1k
views
I'm Jelly of Python (Cops)
What does "jelly" mean in the title?. Robber's thread
Jelly has an "Evaluate the argument as Python 3" atom, ŒV which takes a string as an ...
- 49.4k
8
votes
3
answers
612
views
The Math is Right, But the Answer is Wrong - Robbers
Challenge
The cops created code challenges which result in certain wildly incorrect answers despite correct math. Choose an uncracked, not safe formula from the cop thread.
Your task is to find an ...
- 9,891
14
votes
4
answers
891
views
The Math is Right, But the Answer is Wrong - Cops
Robber Thread here
The Challenge
Choose any numeric* formula, algorithm, or code challenge. Implement it in such a way that the math is correct, but at least one answer is wildly** wrong due to some ...
- 9,891
11
votes
25
answers
1k
views
Almost Illegal Strings, Mark II (Robbers)
This is the robbers' thread for 'Almost Illegal Strings'.
See the cop's thread for information on participating. A section from the post is included here for convenience.
The Robbers' Challenge
Find ...
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24
votes
27
answers
2k
views
Almost Illegal Strings, Mark II (Cops)
Edit 2020-11-06: This challenge has been edited with new provisions to encourage participation. The edits have been bolded for emphasis.
Welcome to a cops and robbers version of Find an Illegal ...
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20
votes
60
answers
6k
views
Guess my password (robbers' thread)
Inspired by this challenge, which got closed. This is meant to be an easier, but no less interesting version of that.
This is the robbers thread of a cops-and-robbers challenge. For the cops thread, ...
- 287
41
votes
68
answers
9k
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Guess my password (cops' thread)
Inspired by this challenge, which got closed. This is meant to be an easier, but no less interesting version of that.
This is the cops thread of a cops-and-robbers challenge. For the robbers thread, ...
- 287
13
votes
9
answers
1k
views
Peel away the layers - Robbers
This is the Robbers thread. For the Cops challenge, see here
As the robbers, your job is to crack the cops' answers. Choose an uncracked, unsafe cop answer and attempt to figure out which languages, ...
- 49.4k
28
votes
14
answers
3k
views
Peel away the layers - Cops
In this cops-and-robbers challenge, robbers must crack cop answers by finding out which languages the cops used.
This is the Cops thread. For the Robbers' challenge, see here
Cops, you are to write a ...
- 49.4k
3
votes
0
answers
128
views
Robbers: There's a fault in my vault! [closed]
This is the robbers' thread. The cops' thread is located here.
Robber rules
Should work for all keys and secrets
Should require the same number or fewer guesses as the cop's fault, to prevent brute ...
- 18.6k
8
votes
0
answers
1k
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Cops: There's a fault in my vault! [closed]
In this game of cops and robbers, each cop will make a vault: a program that stores a secret, and requires a key to unlock. The robbers should find a way to get the vault to reveal its secret without ...
- 18.6k
45
votes
143
answers
12k
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 ...
- 96.5k
73
votes
155
answers
13k
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 ...
- 96.5k
-2
votes
4
answers
791
views
Find the hardest OEIS sequence to golf!
Notice: This question originally had people write comments with a shorter program, rather than new answers. This has been changed so that people with shorter programs can get reputation too. Hopefully ...
- 3,129
27
votes
27
answers
3k
views
Robbers: The Hidden OEIS Substring
This is a Cops and Robbers challenge. This is the robber's thread. The cop's thread is here.
The cops will pick any sequence from the OEIS, and write a program p that prints the first integer from ...
- 58.9k
41
votes
30
answers
4k
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Cops: The Hidden OEIS Substring
This is a Cops and Robbers challenge. This is the cop's thread. The robber's thread is here.
As a cop, you must pick any sequence from the OEIS, and write a program p that prints the first integer ...
- 58.9k