I am currently reading Introduction to Algorithms by Cormen, Leiserson, Rivest & Stein, see https://www.amazon.co.uk/Introduction-Algorithms-Thomas-H-Cormen/dp/0262533057, but am finding it very verbose and slow going.
I was wondering whether anyone knows of any good notes/books that cover (the ordinary) Algorithms and/or Data Structures. I really just need a solid core understanding of these topics.
I like the older books on this subject better. My favorite is "Combinatorial Algorithms, Theory and Practice," by Reingold, Nievergelt, and Deo. It's out of print, but you can usually buy it used on amazon, sometimes for pennies. It's only a third as long as CLRS, so it doesn't cover everything there, but the proofs are much more compact. On the other hand, it uses a somewhat peculiar way to display the algorithms, that may take a bit of getting used to.
I also highly recommend Tim Roughgarden's CS 261 lectures at Stanford. https://www.youtube.com/watch?v=dorq_YA6plQ
There are a couple of more advanced books on combinatorial optimization that I like a lot, but I take it that that's not what you're interested in.
The above recommendations are for finding more concise, intuitive proofs than those in CLSR. For a more cookbook approach, I don't have any recommendations. I usually just try to find things on the Web.