Answer:
/Psedocode to merge two input files into one output file
Declaration
File infile1;
File infile2;
File outfile;
number customer_num1;
number customer_num2;
string last_name1;
string last_name2;
string address1;
string address2;
number property_area1;
number property_area2;
string filename;
Start
// get the reference for both the input files
input filename of first file;
infile1 = open filename in read mode; // customer file1 in read mode
input filename of second file;
infile2 = open filename in read mode; // customer file2 in read mode
// get the reference for the output file
input filename of output file;
outfile = open filename in write mode; // output file in write mode
// if both the files exists and can be opened
if(both input files exists and can be opened) then
// read the first record from both the files
read customer_num1, last_name1, address1, property_area1 from infile1
read customer_num2, last_name2, address2, property_area2 from infile2
// read till the end of one of the file is reached
while(end of infile1 has not been reached and end of infile2 has not been reached)
do
// check if customer_num1 < customer_num2 , then write the records of first file to output file, and read the next record from first file
if(customer_num1 < customer_num2 ) then
write customer_num1, last_name1, address1, property_area1 to outfile
read customer_num1, last_name1, address1, property_area1 from infile1
else // else write the records of second file to output file, and read the next record from second file
write customer_num2, last_name2, address2, property_area2 to outfile
read customer_num2, last_name2, address2, property_area2 from infile2
end if;
end while;
// if first file has not been read till the end, copy the remaining records from first file to output file
while(end of infile1 has not been reached)
do
write customer_num1, last_name1, address1, property_area1 to outfile
read customer_num1, last_name1, address1, property_area1 from infile1
end while;
// if second file has not been read till the end, copy the remaining records from second file to output file
while(end of infile2 has not been reached)
do
write customer_num2, last_name2, address2, property_area2 to outfile
read customer_num2, last_name2, address2, property_area2 from infile2
end while;
// close the input files and output file
close infile1;
close infile2;
close outfile;
else
print("Unable to open input files");
end if;
End
Explanation:
