write an Algorithm, not a code

Question

"NOTE: write an algorithm, not a code"

You are given a file called “std” and composed of “Number, Name, Address” fields/attributes. (You can define the type of fields by yourself) Write an algorithm that makes “insertion, deletion, update and retrieve”, processes on the records in the file. The “Number” field is the key of each record.

Answer 1

Routine which parses one record read from file

==============================================

tokens = inbuff.split(",");

dataRecord.recNum = Int(tokens[0]);

dataRecord.name = tokens[1];

dataRecord.address = tokens[2];

Routine which Serializes the data record buffer

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dataRecordBuff = dataRec.recNum + "," + dataRec.name + "," + dataRec.address

Reads data file

=================

ReadFile( filename, database)

{

opens the file

reads # of records from file

for i = 0 to numRecs-1:

read input buffer

database[i] = parse(input buffer)

endforloop

}

closes the file

Write Data File

================

opens the file

for i=0 to numRecs-1

serialize database(i) to record buffer

writes output buffer to file

closes the file

Linear Search

==============

iIndexPos=-1

for i=0 to numRecs-1

if targetRecord = database(i)

iIndexPos=i

break

return iIndexPos

Insert

=========

if newRecord not found

increases array size by 1

inserts new record at end

sort if necessary

increment record count

write to file

else

record already exist

DELETE

=========

if targetRecord found

moves each record over 1 position to left

decrement record count

write to file

else

record not found

Update

=========

if targetRecord found

replaces old record with new record

writes to file