Microsoft Visual Studio, Create a program to sort a file with 120 ints where only 20 ints can placed into memory at any one time
Budget: $30 – $250 USD
General idea:
Break data into blocks, sort blocks into runs, merge runs
More detailed idea:
Call inFile1 our source file ( the one with the initial 120 records to be sorted.)
You will also need an inFile2, and 2 other files outFile1 and outFile2.
Break the file into blocks of size 20: in this case there will be 6 blocks ( 120/20 )
Sort the blocks by
read a block, sort it, store in outFile1
read a block, sort it, store in outFile2
read a block, sort it, store in outFile1
( in other words, sort a block and alternately place in the files outFile1,
outFile2 )
By definition a run is a sorted block
Note that each file outFile1 and outFile2 will have half of the runs
Merge the runs
Merge data from outFile1 and outFile2 to inFile1 and inFile2.
Merge the first run on outFile1 and the first run on outFile2,
and store the result on inFile1:
Read two records in main memory, compare, store the smaller
on inFile1
Read the next record from either outFile1 or outFile2 the file
that had its record moved/stored to inFile1
Similarly merge the second run on outFile1 and the second run on
outFile2, store the result on inFile2.
Merge the third run on outFile1 and the third run on outFile2, store
the result on inFile1... etc
merging each run and storing the result alternatively on inFile1
and inFile2.
At the end
inFile1 and inFile2 will contain sorted runs twice the size of the
previous runs on outFile1 and outFile2
Now merge data from inFile1 and inFile2 to outFile1 and outFile2.
Merge the first run on inFile1 and the first run on inFile2, and store
the result on outFile1.
Merge the second run on inFile1 and the second run on inFile2,
store the result on outFile2
Etc, merge and store alternatively on inFile1 and inFile2.
Repeat the process until only one run is obtained. This would be the sorted
file
**Must use above algorithm
**MUST use algorithms from sort_algorithms.t:
the algorithms may not be modified. - but you may assume an overloaded < operator
exists. Thus you may remove the pointer to the function cmp ( obviously, the code will have to
replace any reference to cmp, no puns intended, with < )
It is permissible to copy/paste any algorithms from sort_algorithms.t that you use to your own sort_alg.t
Declare a variable MAX_MEM_SIZE, of type size_t. Initialize to 20
If you are really paying attention to the directions, you will realize that 2 arrays of 20 cannot both be in
memory at the same time – depending on how you implement the above algorithm and which
sort you use, you may need to break into blocks of size 10
a sample file to be sorted is provided.
Break data into blocks, sort blocks into runs, merge runs
More detailed idea:
Call inFile1 our source file ( the one with the initial 120 records to be sorted.)
You will also need an inFile2, and 2 other files outFile1 and outFile2.
Break the file into blocks of size 20: in this case there will be 6 blocks ( 120/20 )
Sort the blocks by
read a block, sort it, store in outFile1
read a block, sort it, store in outFile2
read a block, sort it, store in outFile1
( in other words, sort a block and alternately place in the files outFile1,
outFile2 )
By definition a run is a sorted block
Note that each file outFile1 and outFile2 will have half of the runs
Merge the runs
Merge data from outFile1 and outFile2 to inFile1 and inFile2.
Merge the first run on outFile1 and the first run on outFile2,
and store the result on inFile1:
Read two records in main memory, compare, store the smaller
on inFile1
Read the next record from either outFile1 or outFile2 the file
that had its record moved/stored to inFile1
Similarly merge the second run on outFile1 and the second run on
outFile2, store the result on inFile2.
Merge the third run on outFile1 and the third run on outFile2, store
the result on inFile1... etc
merging each run and storing the result alternatively on inFile1
and inFile2.
At the end
inFile1 and inFile2 will contain sorted runs twice the size of the
previous runs on outFile1 and outFile2
Now merge data from inFile1 and inFile2 to outFile1 and outFile2.
Merge the first run on inFile1 and the first run on inFile2, and store
the result on outFile1.
Merge the second run on inFile1 and the second run on inFile2,
store the result on outFile2
Etc, merge and store alternatively on inFile1 and inFile2.
Repeat the process until only one run is obtained. This would be the sorted
file
**Must use above algorithm
**MUST use algorithms from sort_algorithms.t:
the algorithms may not be modified. - but you may assume an overloaded < operator
exists. Thus you may remove the pointer to the function cmp ( obviously, the code will have to
replace any reference to cmp, no puns intended, with < )
It is permissible to copy/paste any algorithms from sort_algorithms.t that you use to your own sort_alg.t
Declare a variable MAX_MEM_SIZE, of type size_t. Initialize to 20
If you are really paying attention to the directions, you will realize that 2 arrays of 20 cannot both be in
memory at the same time – depending on how you implement the above algorithm and which
sort you use, you may need to break into blocks of size 10
a sample file to be sorted is provided.