Structured Programming in Basic Problems

© 1998 by Dr. Thomas W. MacFarland -- All Rights Reserved


     Instructions:   Review the following program and see if you can 
                     predict the outcome by completing a "pencil 
                     trace" of the code.  

                     Program output is provided at the end of this 
                     page.

     Compiler:       The program was prepared using GWBasic, which  
                     requires the use of line numbers.


10 REM This program demonstrates a modular approach to
20 REM the use of a sorting algorithm.
30 GOSUB 1000 'Load the numbers
40 GOSUB 2000 'Sort the numbers
50 GOSUB 3000 'Print the numbers
99 END
1000 READ N
1010 DIM NUM(N)
1020 FOR ROW = 1 TO N
1030   READ NUM(ROW)
1040 NEXT ROW
1999 RETURN
2000 FOR BEGIN = 1 TO N-1
2010   SMALL = BEGIN
2020   FOR EXAMINE = BEGIN+1 TO N
2030   IF NUM(SMALL) > NUM(EXAMINE) THEN SMALL = EXAMINE
2040   NEXT EXAMINE
2050   TEMP = NUM(BEGIN)
2060   NUM(BEGIN) = NUM(SMALL)
2070   NUM(SMALL) = TEMP
2080 NEXT BEGIN
2999 RETURN
3000 FOR ROW = 1 TO N
3010   PRINT NUM(ROW)
3020 NEXT ROW
3999 RETURN
4000 DATA 8, 7, 3, 2, 1, 12, 4, 9, 11
10000 REM And the answer is ...
10010 REM 1
10020 REM 2
10030 REM 3
10040 REM 4
10050 REM 7
10060 REM 9
10070 REM 11
10080 REM 12

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