Lab Quiz Solutions, Foundations of Computing, Week 7 -- Thurs Nov 9 2000

  1. This table shows the number of electoral votes allocated to several states:

    Washington11
    Oregon7
    Iowa7
    California54
    Florida25

    Define a Scheme variable named electoral-votes to encode this table. Represent the table by a list of sublists, one for each state, where the car of each sublist is the name of the state and the cdr of each sublist is a list whose only element is the number of electoral votes for that state.

    (define electoral-votes
      '((Washington 11) (Oregon 7) (Iowa 7) (California 54)
        (Florida 25)))
    
  2. This tree represents the geographic relation of some states, counties and cities in the USA:

                           +------------------ USA -------------+
                           |                                    |
                +----- Washington -----+                     Florida 
                |                      |                        |
        +----- King ----+        +- Thurston -+             +- Dade -+
        |               |        |            |             |        |
      Seattle        Bellevue   Olympia     Lacey         Miami   Hialeah
    

    Define a Scheme variable named usa-tree to encode this tree. Represent the tree as a list whose car is USA and whose cdr is a list of subtrees, one for each of the two states. Continue filling in subtrees until you reach the cities. At each level, the car of the subtree holds the data and the cdr of the subtree is a list of subtrees. At each city, the cdr of the sublist is the empty list to indicate that there are no more subtrees.

    (define usa-tree
      '(USA 
        (Washington 
         (King (Seattle) (Bellevue))
         (Thurston (Olympia) (Lacey)))
        (Florida
         (Dade (Miami) (Hialeah)))))