Questions tagged [stateful]
Challenges involving behaviour that depends on previous invocations of the solution.
13 questions
19 votes
13 answers
2k views
Schrödinger's cat program [closed]
Sandbox Your challenge is to write a program that when first run, will do one of the actions below at random with equal chances of both: A cat program A standard cat program: read everything from <...
- 843
14 votes
6 answers
1k views
Save my secrets!
I have so many secrets and nowhere to keep them! The goal is simple: write a program that lets you save a string and have it be protected by a password. The program will take an alias, password and (...
- 1,363
14 votes
11 answers
4k views
A greeting bot for a colleague from work
I have a colleague at work that works from home every Tuesday and Thursday. At around 8:00 AM he sends us a message with the following text: Hello today I'm working from home In order to relieve him ...
- 13k
49 votes
41 answers
15k views
Shortest code in your language to persist a string across a reboot
Your Programs: You'll write two programs (both in the same language). The storage program takes a string from STDIN and stores it somewhere persistent (see below) and then exits without error. The ...
- 893
12 votes
4 answers
468 views
How many instances are running?
Write an indefinitely-running program that reports how many instances of itself are currently running. Each instance of the program should also report the order in which it was opened out of all other ...
- 7,937
12 votes
4 answers
753 views
Entropic Quine!
Your task is to write a program or function which: When run for the first time, outputs its source code. On subsequent executions, it should output what it output previously, but with one random ...
- 15.6k
14 votes
15 answers
3k views
Permanently self-modifying code
Now, we all know most languages have very simple ways to "self-modify" code. However, what if you were to actually modify the code and edit parts of it...on disk? Your goal is to make code that ...
- 449
23 votes
9 answers
855 views
Incremental Quine
Your task is to write a program or function that outputs the first character of its source code, then the second, then the third... each time it is run. For example, if your program was ...
- 40.4k
49 votes
34 answers
5k views
3... 2... 1... Crash off!
Your task is to write a full program that will continue to count down from 10 every time it is run. The first time you run the program, it should print 10. The next ...
- 15.6k
12 votes
5 answers
2k views
Monkey Island: The Head of the Navigator
Warning: This challenge contains some mild spoilers for The Secret of Monkey Island. Towards the end of the game, you're being led through the catacombs by a magically preserved head of a navigator: ...
- 198k
255 votes
83 answers
85k views
Code that will only execute once
Goal The goal of this challenge is to write code that will execute once and only once. This means basically that it damages the program, script, or environment in some way. If rebooting the system ...
- 2,877
10 votes
3 answers
859 views
Use NVM to tenaciously resume operation whenever aborted
Summary The aim of this challenge is to write a tenacious program. This is a stateful program designed to output a given string, but for which, if the program is aborted at any point during the ...
- 615
4 votes
6 answers
752 views
Write a program to perform set operations.
Your task is to write a program to perform set operations. The operations and arguments are taken from command line in the format program operation [argument]. ...
- 6,140