解题指导

如果发现解决书上的习题有难度，请按照以下几个点推进。

1. Read the material taught in class, and make sure you understand all the definitions, algorithms, theorems and proofs.
2. Read the homework problem. Carefully.
3. If you get stuck, here are some suggestions to get past it:
   • Come up with** a small example**, and see how you would solve that. This is particularly helpful when you're trying to follow an algorithm, or when devising a counter example.
   • Which algorithms / techniques / heuristics taught in class are applicable to the problem at hand? When do they fail and for what reason?
   • Reduce the problem to a problem taught in class. Can the problem be represented as tree? a graph? a flow network? maybe to a less general instance of the problem itself (a graph with negative weight to a graph with unique, non-negative weights)?
   • The notion of sub-problem (divide-and-conquer, dynamic programming, induction) is a recurring theme in this class. Try to identify and solve the sub-problems of the problem at hand.
   • If you are still stuck, come to office hours. Sometimes just a brief meeting can get you pointed in the right direction (or help to back you up from a wrong path, to use a DFS analogy).
   When you write down your solution, re-read what you've written. Is the solution understandable? Does it answer specifically what you've been asked about? Your answers should be clear, and often they will be short.

---

Content is copied from "CMU 15451:Algorithms Design and Analysis" website.