Deo’s book includes answers to selected odd-numbered problems (usually the computational ones, not proofs). Check those first to validate your method.
Even if the book is not about programming, implement a brute-force check for small graphs in Python (networkx library). For example, verify Eulerian cycle conditions on random graphs. Graph Theory By Narsingh Deo Exercise Solution
5.1
Graph theory is visual. For problems involving isomorphism, traversability, or planarity: or planarity: In many engineering circles
In many engineering circles, shared PDFs of “Deo solution manuals” circulate. Be careful: Many are incorrectly solved or contain typos in graph diagrams. Use them only for inspiration, not gospel. Graph Theory By Narsingh Deo Exercise Solution