Many universities offer free PDFs of "Inquiry-Based Learning" (IBL) notes for Graph Theory, which are entirely problem-driven. Conclusion
If you can't find the Marcus PDF or want to supplement your learning, check out these highly-rated "problem-first" books: graph theory a problem oriented approach pdf best
The book is divided into short sections, each ending with a set of problems that lead directly into the next concept. graph theory a problem oriented approach pdf best
Daniel Marcus’s book, published by the Mathematical Association of America (MAA), is the gold standard for this style. It is designed specifically for students to work through independently or in a discovery-based classroom. graph theory a problem oriented approach pdf best
Many professors who teach using the Moore Method (a precursor to the problem-oriented approach) host supplementary PDF problem sets that mirror Marcus's style.