Clique	Independent Set	Vertex Cover
Traveling Salesman Problem	Hamiltonian Cycle	Graph Partition
Vertex Coloring	Edge Coloring	Graph Isomorphism
Steiner Tree	Feedback Edge/Vertex Set

Recommended Books

Approximation Algorithms for NP-hard Problems by Dorit Hochbaum	Computers and Intractability: A Guide to the Theory of NP-Completeness by M. R. Garey and D. S. Johnson	Handbook of Approximation Algorithms and Metaheuristics by T. Gonzalez
Complexity and Approximation: Combinatorial Optimization Problems and Their Approximability Properties by G. Ausiello and P. Crescenzi and G. Gambosi and V. Kann and	Approximation Algorithms by V. Vazirani	Graph Algorithms, 2nd Edition by Shimon Even and Guy Even
Graphs, Algorithms, and Optimization, Second Edition by William Kocay and Donald L. Kreher	Algorithms in Java, Part 5: Graph Algorithms (3rd Edition) (Pt.5) by Robert Sedgewick	Graphs, Networks and Algorithms by Dieter Jungnickel
Algorithms in C, Part 5: Graph Algorithms (3rd Edition) (Pt.5) by Robert Sedgewick

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