There’s no better preparation for coding interviews than going to Leetcode (or similar) and doing problems there. There are lists of recommended problems to do, in increasing difficulty, if one wants to do so.

That said, for some topics, if one doesn’t have experience, starting can be quite difficult. Although there are plenty of resources online nowadays (lots of them free), having a guide on how to actually think and develop an understanding of how to solve each problem can be very helpful.

This book is actually very good at doing this. I had already been practicing for a while before it came into my hands and had at least a basic understanding of most of the problems presented, but still found it useful to go over it. Of course, a book such as this one is no use if one doesn’t actually practice it (without looking at the book’s answers, of course).

The code is in Python, but the algorithms themselves should be usable in any other language On occasion some Python library is used that makes things easier, sometimes without much explanation, but a quick search online will show equivalents in any language easily .

So, for any programmer/software engineer who is probably going to go through interviews in companies that think this kind of question is a good idea, or for people who enjoy Advent of Code but feel a bit out of their depth, I do recommend this book.