[jpamata]

A book that has a similar style to this one (teaching algorithm design) and my personal favourite is Algorithmic Problem Solving by Roland Backhouse.

It just teaches algorithmic problem solving via math, but unlike mathy algorithmic books like CLRS, you only need algebra for this one.

I like how the book, IIRC, starts with invariants, providing the reader the foundational skill needed to notice underlying patterns and to decompose problems.