國立暨南國際大學 102 學年度第二學期小考試卷

1. (10%) Determine whether the following code is correct or not.  If it is correct, predict its output.  If it is incorrect, point out the mistake(s).
   // Defining a struct    (P.354)
   #include <iostream>
   using std::cout;
   using std::endl;
   
   struct Rational
   {
       int numerator;
       int denominator;
   }
   
   
   int main()
   {
       Rational a;
       Rational b;
       a.numerator = 4;
       a.denominator = 6;
       b = a;
       cout << b.denominator << endl;
       return 0;
   }
   
   
2. (10%) Determine whether the following code is correct or not.  If it is correct, predict its output.  If it is incorrect, point out the mistake(s).
   
   // Initialize a struct (P.355)
   #include <iostream>
   using std::cout;
   using std::endl;
   
   struct Rational
   {
       int numerator;
       int denominator;
   };
   
   int gcd(int a, int b)
   {
       if (a == 0)
       {
           return (b == 0 ? 0 : b);
       }
       else
           return gcd(b % a, a);
   }
   
   int main()
   {
       Rational a = { 4, 6 };
       Rational b;
       b = a;
       cout << ( b.denominator /= gcd(b.numerator, b.denominator) ) << endl;
       return 0;
   }
   
3. (10%) Determine whether the following code is correct or not.  If it is correct, predict its output.  If it is incorrect, point out the mistake(s).
   
   // Accessing the Members of a struct (P.358)
   #include <iostream>
   using std::cout;
   using std::endl;
   
   struct Circle
   {
       int x;
       int y;
       int radius;
   };
   
   void MoveCircle(Circle& aCircle, int x, int y);
   
   int main()
   {
       Circle a = { 10, 10, 5};
       MoveCircle(a, 20, 30);
       cout << a.x << endl;
       return 0;
   }
   
   void MoveCircle(Circle& aCircle, int x, int y)
   {
       aCircle.x = x;
       aCircle.y = y;
       return;
   }