# April 2015 Community Challenge

Last time we created and reviewed Simon Says games, and that was a lot of fun.

So, what should we do this time? Feel free to resubmit non-winning ideas from previous rounds, although new ideas are usually more successful.

• Vote for those answers which interest you
• At the end-of-day on Thursday, April 9th, the most-voted post will become the next .

Once the challenge topic is decided, you can post questions on the main-site related to the challenge. The idea is to run the challenge all the way through April... although nothing stops you from posting an "entry" later than that :)

• The entrys would work well as community wikis... What do you think? – Cullub Apr 17 '15 at 18:18
• @cullub on the main site? If it didn't mean reviewers get 0 rep for their high-visibility answers, I would agree, but... – Mathieu Guindon Apr 17 '15 at 18:28

Re-Nominating this one, because I think it's a fun little challenge.

https://codereview.meta.stackexchange.com/a/3786/41243

### Implement a simple calculator

Where the definition of "simple" is whatever you make it - only supports basic arithmetic operators? Fine. It supports scientific notation, exponents and trigonometry? Fine! Takes input from the console? Fine! Toggle between binary, hex, octal and decimal notations? Fine!

The common denominator here, is that you need:

• A way to take user input
• A way to parse/validate user input
• A way to perform the operations in the input
• A way to output the result(s)

Everything else you want to put in, is up to you and the time you can devote to this small project in the limited number of days we have until April is over - be creative!

One small amendment to the original challenge, that was hashed out in the comments.

If your language basically is a calculator (Here's looking at you ) or your language supports an Eval() function, using those features as explicitly excluded.

### Challenge entries

• – nhgrif Apr 2 '15 at 23:31
• nooooooooooo – Morwenn Apr 3 '15 at 8:06
• @Morwenn??? Not another calculator? – RubberDuck Apr 3 '15 at 9:13
• @RubberDuck I remember a time when we had 10 calculators a week posted on CR. – Morwenn Apr 3 '15 at 9:25
• I must have not been around yet @Morwenn. Sounds like the awful FizzBuzz invasion last summer. – RubberDuck Apr 3 '15 at 9:26
• @RubberDuck Or the constant linked-list invasion endemic to Code Review. – Morwenn Apr 3 '15 at 9:28
• codereview.stackexchange.com/q/67480/47826 – bhathiya-perera Apr 3 '15 at 12:35
• Really good idea that can be approached from all skill levels! You got my vote. – Evan Bechtol Apr 10 '15 at 19:32

## Resurrect the Stack Eggs!

If you missed them:

• User must make a selection each round before a 20 second timer finishes
• Selections influence some metrics
• Some options unlock at later stages in the game
• The number of people playing influences the number of votes needed each round (optional for this challenge?)
• I like this. I bet there will even be an on-site playable version that leverages Stack Snippets! – Mathieu Guindon Apr 2 '15 at 18:41
• I was thinking of that. – user34073 Apr 2 '15 at 18:41
• For the record, the real StackEggs source has been published here: github.com/StackExchange/stackegg – Simon Forsberg Apr 2 '15 at 19:58
• @SimonAndréForsberg hmm I guess that kinda ruins it eh – Mathieu Guindon Apr 3 '15 at 0:31
• Why would that ruin it? Not everyone knows C#. Besides, past suggestions have been written hundreds of times before. It wouldn't be hard to find a repo in your language of choice to draw inspiration from. – cimmanon Apr 6 '15 at 19:46
• Isn't this the minigame that slowed SE a lot and that anyone could win by not playing it for a while? – Ismael Miguel Apr 6 '15 at 22:47
• we could rags to riches the code? – Malachi Apr 9 '15 at 16:45

Implement your own version of the ls command on UNIX/POSIX systems. Should be able to handle the -l and -a command line arguments. You can, or are expected to, use the built in POSIX library functions or system calls.

• this seems a little too localized – Malachi Apr 9 '15 at 16:44
• Sounds like an exam question I had once. – Nick Udell Apr 21 '15 at 15:38