substring | fast one-time string searches

This problem should be solved easily using a trie.

The trie node should basically keep a track of 2 things:

1. Child nodes
2. Count of prefixes ending at current node

Insert all strings in the trie, which will be done in O(string length * number of strings). After that, simply traversing the trie, you can hash the prefixes based on the count as per your use case. For suffixes, you can use the same approach, just start traversing the strings in reverse order.

Edit:
On second thought, trie might be the most efficient way, but a simple hashmap implementation should also work here. Here's an example to generate all prefixes with count > 1.

You can achieve what you need without a regex here:

I got it working with JavaScript, although it's not an elegant solution. The following will add position:relative and z-index:50 to the element with CSS class slick-current, and will remove it from the other active slides (since the slick current class changes slides when another slides becomes the current slide) using useEffect:

You could use a regex and extractall:

You need to encrypt with the private key and then decrypt with the public key

How about:

regexp_split_to_table can be used to split the value into strings by the delimiter ;, then you can use split_part to get the first and second parts of the desired result.

Does it make sense to iterate through layers like this and keep adding files (to some target, does not matter for now) and deleting the added files in case they are found with a .wh prefix? Or am I totally off and is there a much better way?

There is a much better way, you do not want to reimplement (with worse performances) what Docker already does. The main reason is that Docker uses a mount filesystem called overlay2 by default that allows the creation of images and containers leveraging the concepts of a Union Filesystem: lowerdir, upperdir, workdir and mergeddir.

What you might not expect is that you can reproduce an image or container building process using the mount command available in almost any Unix-like machine.

I found a very interesting article that explains how the overlay storage system works and how Docker internally uses it, I highly recommend the reading.

Actually, if you have read the article, the solution is there: you can mount the image data you have by docker inspecting its LowerDir, UpperDir, WorkDir and by setting the merged dir to a custom path. To make the process simpler, you can run a script like:

The char type has been legacy since Java 2, essentially broken. As a 16-bit value, char is physically incapable of representing most characters.

Your discovery suggests that the String#substring command is char based. Hence the problem shown in your code.

Instead, use code point integer numbers when working with individual characters.