As noted by sibling, CLRS (https://mitpress.mit.edu/9780262046305/introduction-to-algor...) is perhaps the reigning king of algorithms textbooks.

I haven't read it myself, but Algorithm Design Manual (https://www.amazon.com/Algorithm-Design-Manual-Computer-Scie...) also tends to rank high on recommendation lists, and from looking at its table of contents, it does complement CLRS nicely--there looks to be a better selection of things like constraint satisfication or computational geometry.

read this book -> https://www.amazon.com/Algorithm-Design-Manual-Computer-Scie...

Have you taken an algorithms course?

Working through Skiena's Algorithm Design Manual [0] would be a good start and/or watching his lecture series on Youtube [1].

Other great books include Elements of Programming Interviews [2] which comes in Java, C++, and Python flavors.

It can help to focus on a smaller subset of Leetcode problems to learn the tricks that underlie most of them. Neetcode [3] is a good collection of those problems on which you could focus your time and efforts.

I don't think it's realistic to expect to do well on Leetcode without practicing the above skills to some degree, so I wouldn't be hard on yourself if it's been years since you even looked at the material.

[0] https://www.amazon.com/Algorithm-Design-Manual-Computer-Scie...

[1] https://www.youtube.com/watch?v=dphSwq5jP1A&list=PLOtl7M3yp-...

[2] https://elementsofprogramminginterviews.com/

[3] https://neetcode.io/

Note, there seems to be a 3rd Edition in 2020

https://www.amazon.com/Algorithm-Design-Manual-Computer-Scie...