I'm assuming you want something rigorous - based on the comment you replies to.
Many people will recommend CLRS [0] but I prefer it as a reference, rather than a learning resource. I feel it's very dry and academic.
Instead I'd recommend Tim Roughgarden's series of books Algorithms Illuminated for learning about analysis and algorithms. He also has courses on Coursera and Edx to cover the material. It's thorough rigorous and shows algorithms that apply to different paradigms - lke divide and conquer, graph theory.
Sedgewick and Wayne's Algorithms has a companion website with lots of additional material (heavily Java based) - and courses on Coursera too. Again I think it's more approachable than CLRS while still being detailed and covering the theory.
[1] https://mitpress.mit.edu/books/introduction-algorithms-third...