CSE 130  Fall 2008

                              Sample Exam-2


  (1) [1+1+2+2+2+2] Short questions.

  (a) A void function does not have any return statement.

  (b) Both declarations,  [int*  p;]   and   [int  *p;]   (given  inside
  square brackets for clarity), declare p as an integer pointer.

  (c) What is the storage class of local  variables  declared  inside  a
  function? ___________

  (d) When we declare  an  enumerated  type,  compiler  assigns  integer
  values  to  enumerators/members  of  the enumerated set. What value is
  assigned to yellow in the following example? _____
  enum color { green, red, blue, yellow }

  (e) Using `typedef' declare another type  mycolor  which  renames  the
  type declared in (d).

  (f) Declare a variable y of type mycolor declared in (e),  and  assign
  it a value blue. This should be just one statement.

  (2) (a) [4 points] Sort the array [40, 10, 7,  25,  32]  using  bubble
  sort. Show array after each pass.

  (b) [3 points] Suppose we want to stop bubbleSort algorithm as as soon
  as  array  is  sorted,  what will you check/test to stop the algorithm
  (get out of the loop).  No code is expected just describe an idea.

  (3) [5+1+1 points] For the given array  of  characters,  do  a  binary
  search  looking  for  Y. Show all steps, calculation of midpoints, and
  all comparisons.  How many times did you calculate the midpoint?  When
  did you decide that `Y' is not on the list?  Array ==> [A, E, G, K, M,
  P, Q, R, W] Array index starts at 0.

  (4) (a) [4 points] What value is computed by  the  recursive  function
  mystery for   (i) n = 3? ___ (ii) n = 4? ___ (iii)  and n = 5? ___
  (iv)  and n =  6?  ___

  (b) [4 points]  Function mystery returns either 1 (true) or 0  (false)
  depending on value of n. What exactly function mystery computes/checks
  (when it returns a value back to its calling function)?  Express  your
  answer in terms of parameter n. Assume that n > 0.

  int mystery (int n)                     (b) Space for your answer.
  {
     if (n==0) return 1;
       else if (n==1) return 0;
       else if (n==2) return 0;
     else return mystery (n-3);
  }

  (5) Complete the program given below that finds and prints the  second
  largest element/value of array A.

  int main (void)
  { const int size = 7
    int A[size] = { 7, 31, 8, 4, 10, 20, 5 };
    int index, i = 2;
    int largest = A[0], s_largest = A[1];

    while (i < size)
     {


     }


  }
  (a) [3 points] There is a logical error in the part  of  this  program
  above  while  loop.  What is it, and how will you fix it? Do not write
  code. Just explain.

  (b) [5+1 points] Complete the while loop and print.

  (c) [2 points] Give a list of 7 integers, such that the  this  program
  does  very  little  or  the least amount of work while determining the
  second largest value.

  (6) (a) [2 points] Declare a structure amount with  two  members,  int
  dollars and int cents.

  (b) [2+4 points] Write a function amountCheck that takes  two  parame-
  ters  x  and y of type struct amount. It returns an integer value 0 if
  amounts x and y are equal, else if amount x is less than amount y,  it
  returns  1,  else  it returns 2.  (No credit, if you convert amount to
  cents and check.)

  (7) [6 points] Complete the program given below such  that  the  right
  upper  triangular  part of the array B is initialized to all zeros. Do
  not worry about the rest of B. See the example.

  Example: A 4 x 4 array with its         1  0  0  0
  upper triangular part set to 0.         2  2  0  0
                                          3  3  3  0
                                          4  4  4  4
      int main ()
       {
          const int size = 10;
          int B[size][size];
          int i, j;
          // Write code for Right Upper Triangle Only.
          // Initialize it to all zeros. Do not worry about the rest of B.
          // You do not need extra variables.

  (8) (a) [2+5 points] Write a function err_percent that takes two  dou-
  ble  parameters x and y, and returns the percentage error with respect
  to x. It calculates percentage error by the following formula.

      Percentage_error = (positive difference between x and y)*100/x

  At the end, return percentage_error of type double.  You may use addi-
  tional local variables.

  (9) [6 points] Consider the following program with pointers.
  What values are printed at the end?  f1 = ____, f2 = _____

  int main ( )
  {
     float f1 = 1.0, f2 = 2.0;
     float *fp1, *fp2;

     fp1 = &(f1);
     fp2 = fp1;
     *fp2 = f2 * (*fp1 + *fp2);
     fp2 = &(f2);
     *fp1 = *fp2 + *fp1;

     printf("f1 = %f, f2 = %f\n", f1, f2);
     return 0;
  }