How to make alerts in Golang server with backround processes?

Question

go

Greetings.
I made a service in Golange, with a login and registration system.
It allows registered users to find apartments in London in a specific area (scraper on the site https://www.spareroom.co.uk).
Now I want to implement the following function:
- If you are a registered user, then you can not only search in the area you need, but you can also receive notifications for new apartments in the area that you have set for tracking.
I need advice on how to implement this functionality, something like a background process on the server, perhaps through goroutines that will be launched by each user, and once every 30 seconds make a request for this area, save the results, compare them and output where -something (where?) new apartments for the user to see them.
I'm a beginner and have a very vague idea of ​​how to implement this.

Answer 1

In general, here they act according to the usual algorithm, which can be found on Wiki: https://ru.m.wikipedia.org/wiki/Determinant
In fact, det(B) is an additional minor ( https://ru.m .wikipedia.org/wiki/%D0%94%D0%BE%D0%BF... ). Ie, in a cycle there is a "deletion". The author took this literally and created n! (factorial) additional arrays, which is quite wasteful. You can even rewrite this primitive without additional memory.