CSE2050 Fall 2002 Exam #1, Open book, open notes.  Name __________________

1.  If p and q are iterators, circle the operations that are valid if
they are random iterators, but not if they are bidirectional (2 pts each).

  p==q  p<q  p[3]  p-q  *p  ++p  p--  p+1  p+2  p+q

ANSWER

  Circle: p<q p[3] p-q  p+1 p+2
  (p+q is not valid for any iterator type, -1 point if circled).

2.  Suppose s is a string.  Use transform() to replace each
character c with tolower(c).  (10 pts).

ANSWER

  transform(s.begin(), s.end(), s.begin(), tolower);


3.  The function f() takes no arguments and returns void, but might throw
exceptions of type domain_error or bad_alloc (out of memory).  Write code
that calls f() and prints the type of exception it threw, if any (15 pts).

ANSWER

  try {
    f();
  }
  catch (domain_error e) { // Don't forget the object, domain_error is a type
    cout << "domain_error";  // or e.what();
  }
  catch (bad_alloc e) {
    cout << "bad_alloc";  // or e.what();
  }


4.  Write a function taking a map<int, bool> (using the most appropriate
parameter passing technique) and printing (in ascending order) a list
of keys for which the value is true (25 pts).

ANSWER

  void print(const map<int, bool>& m) {
    for (map<int, bool>::const_iterator p=m.begin(); p!=m.end(); ++p)
      if (p->second)
        cout << p->first << endl;
  }


5.  On the back, write an appropriate header file for p1.cpp and p2.cpp.
Show the g++ command to compile and link them into a single program (30 pts)

  // p1.cpp
  #include <string>
  #include "p.h"
  void set(Record& x, const std::string& name, int age) {
    x.name = name;
    x.age = age;
  }
    
  // p2.cpp
  #include <iostream>
  #include <string>
  #include "p.h"
  using namespace std;
  int main() {
    Record r;
    set(r, "Matt", 47);
    cout << r.name << " " << r.age << endl;
    return 0;
  }

ANSWER

  // p.h
  #include <string>
  struct Record {  // Must be before declaration for set()
    std::string name;  // No "using namespace std;"
    int age;
  };
  void set(Record&, const std::string&, int);  // parameter names optional


  To compile:
  g++ p1.cpp p2.cpp