Answers to Sample Midterm Questions
(other answers may be possible in some cases)

1. a
2. b
3. d
4. e
5. e
6. c
7. false
8. true
9. false
10. false
11. true
12. true
13. false
14. true
15. true
16. max >= 0, contents.size() <= max
17. public
18. private
19. public (and possibly final)
20. REQUIRES: If N is the number of vertices passed to the constructor,
              0 <= vertex1 < N and 0 <= vertex2 < N.
21. MODIFIES: this
22. EFFECTS:  Creates an edge from vertex1 to vertex2 with the given weight,
              replacing the old weight, if any.
23. REQUIRES: If N is the number of vertices passed to the constructor,
              0 <= vertex1 < N and 0 <= vertex2 < N.
              There is an edge from vertex1 to vertex2, or there is vertex k
              with an edge from vertex1 to k and an edge from k to vertex2.
24. MODIFIES: nothing
25. EFFECTS:  nothing
26. RETURNS:  The shortest path length from vertex1 to vertex2 via at most
              one intermediate vertex.
27. Yes.
28. The indirect method does not declare that an exception is thrown, yet it
    throws a NoSuchPathException, so that must not be a checked exception.
29. An ArrayIndexOutOfBoundsException would be thrown.
30. Could check the bounds and throw an IllegalArgumentException indicating
    that there is no such vertex.
31. G(x) = (V,E) where
       V = { i : edges[i][j] != 0 for some j }
       E = { (i,j) with weight w : edges[i][j] == w and w != 0 }