Re: Fibonacci program

Judson McClendon wrote:
Good first try, but you didn't use ON SIZE ERROR. Since you did your own work, I don't mind helping you more. Check out this version and see if you like it better:

       IDENTIFICATION DIVISION.
       PROGRAM-ID.    Fibonacci.
       AUTHOR.        Judson McClendon.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       77  Fib             PIC  9(09)  VALUE 1.
       77  Fib-1           PIC  9(09)  VALUE 0.
       77  Fib-2           PIC  9(09)  VALUE 0.
       PROCEDURE DIVISION.
       DO-IT-TO-IT.
           DISPLAY "Fibonacci"
           DISPLAY "*********"
           PERFORM UNTIL (1 < 0)
               DISPLAY Fib
               MOVE Fib-1 TO Fib-2
               MOVE Fib   TO Fib-1
               COMPUTE Fib = Fib-1 + Fib-2
                   ON SIZE ERROR
                       EXIT PERFORM
               END-COMPUTE
           END-PERFORM
           DISPLAY "*********"
           STOP RUN.

Good on you Spartacus for figuring it out. Just for info, here's mine to compare to what Judson produced - not too dissimilar :-

       Program-id.     Fibonacci.

       WORKING-STORAGE SECTION.

       01 n                   pic 9(09).
       01 ANumber occurs 3    pic 9(09).
       01 ws-display          pic zzz,zzz,zzz blank when zero.

       01 ProgramFlag         pic 9.
          88 ContinueProgram  value 0.
          88 CancelProgram    value 1.

       PROCEDURE DIVISION.

       *> Note : I have a 'forever' PERFORM - it will never
       *> achieve CancelProgram. My reasoning - if your
       *> Instructor said 'Now change the fileds to pic 9(12)
       *> and the ws-display", it will work up to the current
       *> maximum  of pic 9(18).

       set ContinueProgram to true
       Move 1      to ANumber(1)
       move zeroes to ANumber(2)
       perform varying n from 1 by 1 until CancelProgram

          COMPUTE  ANumber(3) = ANumber(1) + ANumber(2)
                   On Size Error
                      compute ws-display = n - 1

       *> The on size error occurs on the 44th,
       *> not 45th iteration

                      Display " "
                      Display "There were", ws-display
                      " Iterations before exceeding 999,999,999"
                      EXIT PERFORM
                   Not On size Error
                      move ANumber(3) to ws-display
                      display ws-display
          END-COMPUTE

          move ANumber(2) to ANumber(1)
          move ANumber(3) to ANumber(2)

       End-perform

       STOP RUN.
.

Relevant Pages

  • Re: Fibonacci program
    ... PROGRAM-ID. ... DISPLAY "Fibonacci" ... Your code is FULLY ANSI/ISO '85 Standard conforming ... DISPLAY "Fibonacci Sequence" ...
    (comp.lang.cobol)
  • Re: Fibonacci program
    ... Fibonacci. ... > PROGRAM-ID. ... > WORKING-STORAGE SECTION. ... > DISPLAY "Fibonacci Sequence" ...
    (comp.lang.cobol)
  • Re: Fibonacci program
    ... PROGRAM-ID. ... Spartacus. ... DISPLAY "Fibonacci Sequence" ...
    (comp.lang.cobol)