CSE 130

                    Solutions Sample Exam-1


  1. (a) Yes (b) No (c) No (d) Yes (e) Yes

  2. (a) False (b) 8 (c) True (d) False

  3.  switch (class)
        {
          case 1: dues = 100 + salary * 0.02;
                  break;

          case 2: dues = 50 + salary * 0.01;
                  break;
       
          default: printf("Wrong class"); }

  4. (a) No error (b) Type should be char and not character.
     (c) constant in place of const (d) !== is not a valid
     opeartor.

  5. The innermost for loop must have only one statement that
     prints a[j]. It does not need a body. But after every row,
     we must print \n. So outer for loop has two statements.
     The first one is a the inner for loop, and the second one
     that prints \n. Actually we want two \n's here. See the
     comment below.

     # include <stdio.h>
     int main ( )
       { int i, j;
         int a[5] = {0, 1, 2, 3, 4};
    
         for (i = 4; i >= 0; i--)     // worth 4 points.

      -->    { for (j = i, j >= 0; j--)

                printf("%d", a[j]);  // worth 2 points.

                printf("\n"); } <---  Insert { } here. 2 points

                // Actually, here we want two \n, like \n\n.
                // I forgot to include that. One student pointed
                // that out. We did not deduct any points for this.
        
     return 0;
   } 

  6. (a) 10 (b) 6
    
     (c)    int sum = 0, n;
            n = ??? // some value

            if (n < 0) n = -n;  // Move this outside.

            while (n > 0)
             { sum = sum + n;
               n = n-1; }

  7.
     # include <stdio.h>
     main ( )
     { int distance, speed, hours, minutes;
       float time;

       printf ("Enter distance and speed: ");
       scanf ("%d%d", &distance, &speed);  <---

       time = ((float)distance)/speed;

       hours = (int)(time);  <-- Get the integer part.

       // time - hours is minutes in decimal. Multiply by 60,
       // and cast to an integer.

       minutes = (int) ( (time - hours)*60 );    

       printf ("Time required: %d hours and %d minutes", hours, minutes);

      }

   8.   int even (int m)     // 2 points
        {
          if (m%2 == 0) return 1 else return 0; }   // 3 points

   9 (a) Just a simple swap, there was no need to write scanf and
         printf statements.

         temp = A[p];  A[p] = A[q];   A[q] = temp;

     (b) One if statement was expected. Both p and q should be >= 0
         and <= 6. Anything else would be an error.

         if ( (p < 0) || (q < 0) || (p > 6) || (q >  6) ) error = 1;
            else error = 0;

         Inner brackets are added for clarity. They are not
         required. If any of the 4 conditions are violated then
         we have an error. That why we use OR operation (||).