It's the final week of term! I hope you've managed to have a fun and useful first term despite the current global situation.

Sadly there's no talk this week, but don't forget that you can watch all of this term's talks (and last term's talks) on our YouTube channel! If you're feeling inspired after watching a few, why not submit your own talk for Spring term?

The call for abstracts for the BCSWomen Lovelace Colloquium 2021 is now open! Submit your 250 word abstract for a chance to enter the poster content, which will take place online this year.

See the BCSWomen site for more info and to submit your abstract!

Film Night - 19:00, Fri 04/12 - HackSoc Discord (The Pod)

We gather together in our Discord server to watch a film (or sometimes several). Apparently some of these might have a link to Computer Science, but we haven't spotted one yet.

Vote for the film you'd like to watch using our Film Night Portal!

We'll use our very own live-streaming platform to watch the film together. Hop into our Discord server at 7pm, and the film will begin after some time to catch up with your fellow members. (If you wouldn't like to hear any conversation during the film, then you're welcome to mute and deafen yourself!)

Alice is wrong, as shown by the following puzzle square:

TODO PASTE AN IMAGE

Alice’s method would find:

TODO PASTE AN IMAGE

But the correct answer is:

TODO PASTE AN IMAGE

Bob is also wrong. Dijkstra's algorithm can be used to find the solution. Dijkstra's algorithm’s worst case complexity is O( |V|+|E|log(|V|) ) where V is the set of vertices and E is the set of edges. We can represent our problem as a set of vertices and edges which gives us |V| = N², and |E| = ( N(N-1) + 2(N-1)² ) which is asymptotically equivalent to |E| = N². So overall with Dijkstra's algorithm we get O(N² + N²log(N²)) or O(N²log(N²)) asymptotically.

A secret organization is conspiring to steal the HackSock, you have successfully found two scraps of the code books with which they encrypt their secret messages to each other.

As well as acquiring the scraps of the code book, you also intercepted the start of two messages sent with them.

The first message starts {19, 24, 42, 61, 94…} and the code book scrap has the numbers 5, 3, 4 written in that order on it.

The second message starts {12, 15, 28, 38, 57…} and the code book scrap has the numbers 2, 4, 3 written in that order on it.

What is the code?

Make sure you're in HackSoc's Slack workspace! We have over 200 members, and it's free to join the conversation, so sign up now!

If you're joining us for any of our virtual events, make sure you're also in our Discord server.

Have a great week,

Aaron 🤖