In the musical rendition of Les Miserables, a song appears called "Red and Black." Here is part of that song: Red - the blood of angry men! Black - the dark of ages past! Red - a world about to dawn! Black - the night that ends at last! Source Your task is to turn input ...

Range without Range Builtin Challenge Given an integer y where y > 0, output a list of in some reasonable format that contains every integer in increasing order up to but not including y, without using any builtin that generates a range of any sort. If your language has a feature whose specific...

Interleaving reversing code-golfstring Given a string, reverse it interleavingly. Here's how to do it for abcdefghi and abcdefghij, 0-indexed: Separate the chars at even indices from the chars at odd indices:a c e g i b d f h a c e g i b d f h j Reverse the chars at odd indices:a c e g i h...

Given an unordered collection of positive integers by any reasonable input method, return all of the sub-collections that have an odd number of odd elements (i.e. have an odd total). For example; [2, 3, 7, 2] -> [3], [7], [2,3], [2,7], [2,2,3], [2,2,7] This is code-golf so you should aim to m...

Draw a complete graph (Connections) code-golf math geometry In mathematics, a complete graph is a simple undirected graph in which every pair of distinct vertices is connected by a pair of unique edges, one in each direction. Challenge The challenge is simple, while your program will likel...

I see from this SMBC comic that Zach Weinersmith is offering a generous 14 points to anybody who can find a way of generating the following series: 0, 1, 4, -13, -133, 52, 53, -155 Now, we all know that there are infinite ways of generating any given numeric series, so Zach is clearly just giv...

EDIT the transcript is broken too The sandbox chat is broken. A message was posted by minxomat and I'm not sure what it is, but it causes chat.stackexchange to stop operating. Sandbox can't load, and it will also freeze other chat windows. I do not recommend opening sandbox chat but the transcri...

The strange attraction of the logistic map code-golf graphical-output math number The purpose of the challenge is to approximately plot the attractor of the logistic map as a function of its parameter r (also called bifurcation diagram), or a subregion of it. The appearance of the graph can be ...

Warning: this post will contain things that people don't want to hear. But it needs to happen. Now that that's out of the way, let's get down to business. The Sandbox was a brilliant idea. It allowed people to see what others thought of their challenges before actually posting them. It was a ...

Show key code Inspired by the showkey command. Task You have to output the key and if is a key-up or a key-down event. I exemplify: The output I want: Key X Down Key X Up for both the instants you press or release a key. You can output it on a console or on a GUI. It is code-golf, so s...

Hurry up, the time bomb is ticking! code-challenge cops-and-robbers kolmogorov-complexity Challenge - Both teams All users are divided into two teams based on their PPCG ID. One for the even IDs and one for the odd IDs. Each user has two options: Start a new bomb Perform a counterattack ...