Hi All,
The following problem solution has given me fits!!!:mad: The problem states that a library records monthly book withdrawls, capturing the Library of Congress Number, Author and Title, for each month (sorted by the Library of Congress Number for each withdrawl). The initial problem required the merger of the January and Feburary files - which I was able to do without difficulty, but the follow-on problem required that any redundant records, regardless of file of origin, not be written to the merged file. I think I've gotten it, but I've gone through it so many times by now that I'm not sure if I really have it, or if I'm just chasing my tail trying to get a solution. Any help/pointers would be greatly appreciated!
FYI I've included code blocks for the overall program as well as each component module, but it's the mainLoop() module that I'm actually concerned about.
Program pseudocode
comment: merge files "janResources" & "febResources" w/o writing duplicate
comment: resource information (ie, ...LibCongressNum, ...Author & ...Title)
comment: assignment operator is "=" and equals comparison operator is "=="
Start
perform houseKeeping()
while bothAtEof == "N" then
perform mainLoop()
endwhile
perform finishUp()
Stop
houseKeeping() module pseudocode
houseKeeping()
declare variables:
comment: file: "janResources"
char janLibCongressNum = null
char janAuthor = null
char janTitle = null
comment: file: "febResources"
char febLibCongressNum = null
char febAuthor = null
char febTitle = null
comment: end processing flag variable
char bothAtEof = "N"
comment: record comparison variable
char previousLibCongressNum = null
comment: files: "janResources" & "febResources"
open files
read janResources
if eof then
janLibCongressNum = "ZZZZZZZZZZ"
endif
read febResources
if eof then
febLibCongressNum = "ZZZZZZZZZZ"
endif
if janLibCongressNum == "ZZZZZZZZZZ" then
if febLibCongressNum == "ZZZZZZZZZZ" then
bothAtEof = "Y"
endif
endif
return
mainLoop()pseudocode
mainLoop()
comment: if the value of "janLibCongressNum" is < "febLibCongressNum", the
comment: assumption is that "janResources" is not at eof & the record must
comment: be written; subsequent comparison of "janLibCongressNum" ensures
comment: that duplicate resource info is not written to file.
if janLibCongressNum < febLibCongressNum then
if janLibCongressNum == previousLibCongressNum then
while janLibCongressNum == previousLibeCongresNum then
read janResources
endwhile
if eof then
janLibCongressNum = "ZZZZZZZZZZ"
endif
else
set previousLibCongress = janLibCongressNum
write janLibCongressNum, janAuthor, janTitle
read janResources
if eof file then
janLibCongressNum = "ZZZZZZZZZZ"
endif
endif
else
comment: if the value of "janLibCongressNum" is > "febLibCongressNum", the
comment: assumption is that "febResources" is not at eof & the record must
comment: be written; subsequent comparison of "febLibCongressNum" ensures
comment: that duplicate resource info is not written to file.
if febLibCongressNum < janLibCongressNum then
if febLibCongressNum == previousLibCongressNum then
while febLibCongressNum == previouLibCongressNum then
read febResources
endwhile
if eof then
febLibCongressNum = "ZZZZZZZZZZ"
endif
else
set previousLibCongressNum = febLibCongressNum
write febLibCongressNum, febAuthor, febTitle
read febResources
if eof then
febLibCongressNum = "ZZZZZZZZZZ"
endif
endif
else
comment: if the value of "janLibCongressNum" equals "febLibCongressNum",
comment: it must be determined if either record (or both), is a duplicate
comment: record - the easiest way to do this is to determine if the equity
comment: value has already been written, requiring one or the other
comment: variable's value to be compared to the last record written & then
comment: letting the next iteration of "mainLogic()" to process the other
comment: equity value; for simplicity the "janLibCongressNum" variable was
comment: chosen for the first equity camparison.
if janLibCongressNum == febLibCongressNum then
if janLibCongressNum == previousLibCongressNum then
while previousLibCongresNum == janLibCongressNum then
read janResources
endwhile
if eof then
janLibCongressNum = "ZZZZZZZZZZ"
endif
else
set previousLibCongressNum = janLibCongressNum
write janLibCongressNum, janAuthor, janTitle
read janResources
if eof then
janLibCongressNum = "ZZZZZZZZZZ"
endif
endif
endif
endif
endif
if janLibCongressNum == "ZZZZZZZZZZ" then
if janLibCongressNum == "ZZZZZZZZZZ" then
bothAtEof = "Y"
endif
endif
return
finishUp() pseudocode
finishUp()
close files
return
TIA
Offline 
Unsolved 
