[cs13001] sample midterm exam

[Mikhail Nesterenko]

CSI students,

To help you in midterm exam preparation, I am attaching the exam that was given
in CSI last year.

Thanks,
-- 
Mikhail


--------------
              CS 13001 "Computer Science I"

                       EXAM #1
The number of points for each question is given in square
brackets. For all
code fragments below assume that appropriate #include and "using"
directives
were provided.


1.[10] Consider the following code fragment:

            string s1 = "Hi", s2 = "Hello", s3;
            s3 = (s1 < s2) ? s1 : s2;
            cout << s3;

       Write out what output this code generates. Name the operation
       on the second line of the fragment and explain how it operates.
       Rewrite the second line using either branching or looping
       statements.


2.[10] Explain the differences between prefix and suffix form of the increment
       operator. Consider the following code fragment:

            int a=3, b=4, c;
            c = (a++) - (++b);
            cout << a << " " << b << " " << c;

       What output does it generate? Explain your answer.


3.[10] Explain the difference between while and do-while looping
       constructs. Rewrite the following code with either while
       or do-while.

               for(int i=0; i < 10; i++)
                  cout << i << ' ';


4.[15] Describe how "break" and "continue" statements work with
       looping constructs. Consider the following code fragment:

            int i=0;
            while (i < 10){
                i++;
                if (i > 5) break;
                cout << i << " ";
            }
            cout << i;

        What out would this code generate? How would the output change
        if "break" is replaced by "continue"?  Explain your answers.
        For both cases write out the exact output.


5.[10] Define the notion of variable scope. Consider the following code
       fragment:

            int a = 3;
            if (a > 0) {
               double a = 10.0;
               cout << a << " ";
            }
            cout << a;

      Write out what output this code generates. Explain your answer.


6.[15] Name and explain parameter-passing disciplines we studied.
       Consider the following code fragment:

               int function1(int);
               int function2(int&);

               int main(){
                   int a=3, b=4;
                   int c = function1(a);
                   int d = function2(b);
                   cout << a << " " << b << " " << c << " " << d;
               }

               int function1(int aa){
                   aa++;
                   return aa;
               }

               int function2(int &bb){
                   bb++;
                   return bb;
               }


        Write out what output this code generates.  Explain your
        answer.

7.[15] Consider the following code fragment:

            const int SIZE=10;
            int myarray[SIZE];

            // here goes the code that assigns the array
            // values to each element of the array
            // assume it already exists do not write it

            int number;
            cout << "Input the number to search for: ";
            cin >> number;

            //
            // here goes the code you need to write
            //

        Complete this fragment such that the resultant code checks
        whether the input number is in the array "myarray" and outputs
        the result. Specifically, your code needs to produce one of
        the two outputs

        example one:

             Input the number to search for:  60
             FOUND

        example two

             Input the number to search for: 33
             NOT FOUND

         That is, depending on the input your code needs to output
         either "FOUND" or "NOT FOUND". Write out the code. Explain
         how it works.


8.[15] Describe what structures in C++ are and what their purpose
       is. Explain what structure variable and member variable are.
       Assuming the following structure definition.

               struct exampleStruct {
                  int a;
                  string b;
               };

       consider the below code:

                exampleStruct x[10];

       Write code that assigns a value to every member variable of the
       fifth element of the array "x". The value is of your choosing.
       Explain the operation of your code.