LBS290F                     STUDY GUIDE                       Winter 1992

Date:  02/26/92


1.    Find the syntax errors in the following program which would
      cause the program not to compile.
      
            REAL X,Y,A(10)
            INT I,J,K
      *
            FOR 10 I=1,10
        10  A[10] = 30
      *
            IF ( Z.LT.100 ) THEN
              Z = 100.0
            END
      
            ELSE IF ( X.GT.100 ) THEN
              Z = X - 1
            ENDIF
      
            X = 100.0
            Y = X - X ** 2
            PRINT *, Y
            READ(*,*,EMD=200)A
            CALL SUB(X,Y)
      200   PRINT *,A
            END
            SUBROUTIME (SUB,X,Y)
            REAL X,Y
            X = Y + 1
            RETRUN
            END


2.     Write a program which will prompt for three values which are
       the coefficients of a quadratic equation.  Then prompt for a value
       for X.  Then evaluate the quadratic equation and print the value
       of the equation.

       Example execution of the program:

         $ a.out
          ENTER A,B,C
          1 2 1
          ENTER X
          3
          COMPUTED VALUE = 16
         $

LBS290F                          STUDY GUIDE                       Page 2


3.     Find at least 4 logic errors in the following program:

             REAL X,Y,Z,A(10),SUM
             INTEGER I,J,K
      *
             READ *,A
             DO 5 I=1,10
             SUM = SUM + A(1)
      5      CONTINUE
             PRINT *,'THE SUM OF ALL OF THE ELEMENTS OF A IS ', SUM
      *
             DO 10 I=1,10
      10     A(I) = (I ** 2) - 1
      *
             CALL SUB(X,Y)
      *       
             PRINT *,X,Y
             Y = Y - SQRT(10.0 - A(10) )
             WRITE(20,*)A
      20     FORMAT(1X,10F7.2)
             END
             SUBROUTINE SUB(I,J)
             INTEGER I,J
             I = 0
             J = -100
             RETURN
             END
       

4.     Write a program which will read an unlimited number of integers
       until end of file and print the sum of the numbers and average
       of the numbers.  Do not use an array.

LBS290F                          STUDY GUIDE                       Page 3


5.      What will the following program print out?


            REAL X,Y,A,B(10),FUNC
            INTEGER I
            DO 10 I=1,10
            B(I) = I ** 2
      10    CONTINUE
            DO 20 I=10,2,-1
            B(I) = (B(I) + B(I-1)) / 2
      20    CONTINUE
            PRINT *,'B(5) is ',B(5)
      *
            X = 100.0
            Y = 17.0
            Z = 24.3
            A = 10.0
            Z = FUNC(X,Y,Z)
            PRINT *,'BACK ',X,Y,Z,A
            END
            FUNCTION FUNC(Y,X,Z)
            REAL X,Y,Z,A
            PRINT *,'FIRST ',X,Y,Z
            A = 35.0
            Z = 32.0
            X = 1.0
            Y = 2.0
            FUNC = -25.0
            PRINT *,'SECOND ',X,Y,Z,A
            RETURN
            END
     
      


LBS290F                          STUDY GUIDE                       Page 4

6.   Write a program which will prompt the user for a single integer.
     The program will find all of the values which can be evenly divided
     into the number with no remainder.  If there are no numbers which 
     can be evenly divided into the number, print 'THE NUMBER IS PRIME'.

     Example executions:

     $ a.out
     ENTER A VALUE
     20
     FACTORS:
      2
      4
      5
      8
     10 
    $ a.out
    ENTER A VALUE:
    17
    FACTORS:
    THE NUMBER IS PRIME
    $