"The Algorithm Design Manual", by Steven Skiena, is very readable and it's generously free to download. I was going to post the link, but I couldn't unmangle it from Google. It's easy to find.
I don't see any links to it from any of Skiena's or the publisher's webpages, so it's not clear how legitimate it is.
Incidentally, I wouldn't really suggest Skiena as an alternative to Cormen et al; they're extremely different in style and content, and in situations where you need one of them the other probably won't help you. I recommend getting both. (For more verbosity on this, see my review of the first edition of Skiena's book at https://www.mccaughan.org.uk/g/books/alg-design.html .)
CLR is information-dense and authoritative. I have a copy from my college algorithms course and I refer to it occasionally. Skiena is a lighter read, so, I figure, you're more likely to actually read it. Whatever algorithms text you read, you will want to continue to augment your knowledge if you're going to confidently adapt and engineer algorithms.
"Introduction to Algorithms"
https://www.amazon.com/Introduction-Algorithms-Thomas-H-Corm...