🎓 Doc Freemo 🇳🇱 @freemo@qoto.org

It feels neglected and wants to leave.

I didn't intend to hurt your feelings, #Java...

(🤣)

Today's retro computer is the Ural. Back when you sat at the computer instead of the computer sitting on you. Nice clean desktop free of clutter.

Nothing can make me as happy today as this post by Erik Bernhardsson, in which he simulates buffet lines to figure out the best queueing method. It involves simulation by way of random food emoji (and a bunch of graphs). https://erikbern.com/2019/10/16/buffet-lines-are-terrible.html

#joke

Why do riot police show up to work early?

To beat the crowds.

Here is a #toyprogrammingchallenge which corresponds to the general case of a problem I ran up against recently.

Given a positive integer K and a directed graph G with weighted edges, return a new graph H satisfying all the following conditions, if such a graph exists:

1. G and H contain exactly the same set of vertices.
2. H contains only edges in G, but G may contain edges not in H.
3. A path exists in H of length at most K between each pair of vertices in each direction.
4. No edge can be removed from H while still satisfying condition 3.

Where more than one graph exists satsifying these conditions, return the one with the least total weight. You may assume G does not contain edges with negative weights.

Here is an example G, each triplet representing the <start, end, weight> of an edge:
<1, 2, 40>
<1, 3, 12>
<1, 4, 50>
<2, 1, 84>
<2, 3, 19>
<2, 4, 69>
<3, 1, 25>
<3, 2, 78>
<3, 4, 93>
<4, 1, 75>
<4, 2, 36>
<4, 3, 96>

Your program should produce the following H given the above G and K = 2:
<1, 2, 40>
<1, 4, 50>
<2, 1, 84>
<2, 3, 19>
<3, 1, 25>
<4, 2, 36>

@Absinthe

The code isn't that bad, you just have to be careful you don't go down a dead end with your algorithm. It's much easier to add error checking etc. at the end if you designed a versatile solution than it is to try and generalise one of the more brittle ones.

Would you mind if I suggested a challenge? I have one involving graph manipulation, which is kind of up @freemo's alley.

@khird @freemo It is pretty well cleaned up now. and I fleshed out the list a little to make it iterable and printable and stuff. Take a peek!

Please suggest one, just remember to include the hash tag

#toyprogrammingchallenge

The Pillars of Creation in the Eagle Nebula #space #universe

Our #GOSH is decolonial

openhardware.science/gosh-manifesto

sway on Reform 2 prototype

#toyprogrammingchallenge

Freebie!! Here you go!
This problem was asked by Facebook.

A builder is looking to build a row of N houses that can be of K different colors. He has a goal of minimizing cost while ensuring that no two neighboring houses are of the same color.

Given an N by K matrix where the nth row and kth column represents the cost to build the nth house with kth color, return the minimum cost which achieves this goal.