CSE 143, Summer 2000
Midterm 1
Programming Problem, Sample Solution

18.  MINDREADING PROBLEM (worth 3 multiple choice questions)

Here is the implementation of a method of a certain class.
Assume that this method is correct and uses no global
variables or constants of any kind.  Write a class
declaration that shows as much as you can reasonably deduce
about the class, just from this code.  Assume the author
follows a style guideline similar to the one used in this
course.

bool 
Browser::updateNodeCount(int urlIndex) {
    Browser tempBrowser(5, 475.33);
    bool result; 
    tempBrowser.setIndex(&result, urlIndex);
    nodes = 1 + tempBrowser.nodeCount();
    return result; 
}



// sample solution

class Browser {
public:	      

  // Strictly speaking, there isn't necessarily a default
  // constructor, but it's likely.
  Browser();

  // Parameter names are arbitrary.
  Browser(int n, double x);  

  // We assume these methods are public, though that's not
  // necessarily the case.

  // obvious from the given definition
  bool updateNodeCount(int urlIndex);

  // Void return type is assumed, but not necessarily the
  // case.  Note that result's type is bool *, not bool &.
  void setIndex(bool *r, int i);

  // int is most likely return type, given expression 1 +
  // tempBrowser.nodeCount() above
  int nodeCount();
    
private:

  // Member variables tend to be private in well-designed
  // classes, so nodes is declared here, not above.

  // most likely type, given expression 1 +
  // tempBrowser.nodeCount() above
  int nodes;
};