Description
Purpose:
* Demonstrate (elementary) understanding of imperative and
lambda programming in Java.
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Background:
* The sum of cubes function takes one argument, n, and returns
the value of n cubed plus the value of the sum of cubes
function of n-1. The value of the sum of cubes function
of n == 0 is 0.
* The pseudo-Pell function takes one argument, n, and returns
the value of three times the value of pseudo-Pell function
of n-1 plus two times the value of the pseudo-Pell function
of n-2. The value of the pseudo-Pell function of n == 1 is 1.
The value of the pseudo-Pell function of n == 0 is 0.
* The GCD function takes two arguments, m and n. If n == 0,
GCD returns m. Otherwise, GCD returns the value of the GCD
function of n and m mod n.
* The sumOfCubes() function should be called for n = 0 up to
and including 15.
* The pseudoPell() function should be called for n = 0 up to and
including 15.
* The GCD() function should be called for m = 1 up to and
including 10 and n = 1 up to and including 10. The m loop
should be outermost and the n loop innermost.
* The arguments and results of each call should be printed in
messages matching those shown in outputdata.txt.
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Tasks:
1. Download HMWK_05_dalioba.zip from Blackboard.
2. Unzip the file somewhere convenient.
3. Change ‘dalioba’ in the name of the directory to your NetID.
(Your NetID is three letters followed by four or five digits.
The directory name will now be something like
‘hmwk_05_abc1234’, with YOUR NetID instead of ‘abc1234’.)
4. Look in that directory.
5. Change the header lines in the template files
hmwk_05_imperative.java and hmwk_05_lambda.java.
— Line 1: Family name first, then a comma, then
personal name.
— Line 2: Your NetID.
— Line 3: The date you edited the file.
6. In hmwk_05_imperative.java write the three RECURSIVE Java
functions sumOfCubes, pseudoPell, and GCD. (The spots to put
the functions are marked with comments.) Write loops to call
these routines the appropriate number of times from the
main() function.
7. Compile and run the hmwk_05_imperative.java file. Your
output should match that given in the outputdata.txt file.
8. Now, in the hmwk_05_lambda.java file, write three LAMBDAs
that accomplish the same functions as sumOfCubes, pseudoPell,
and GCD. (The spots to put the lambdas are marked with
comments.) Write loops to call these routine the appropriate
number of times from the main() function.
9. Compile and run the hmwk_05_lambda.java file. Your
output should once again match that given in the
outputdata.txt file.
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Submission:
Make a zipfile of your ‘hmwk_05_abc1234’ directory (where
‘abc1234’ is replaced with YOUR NetID) and submit it on Blackboard
as your results for this assignment. Your submission should be a
zipfile that has exactly one item in it, a directory named
‘hmwk_05_abc1234’ (where ‘abc1234’ is YOUR NetID). Inside that
directory should be your two source files, hmwk_05_imperative.java
and hmwk_05_lambda.java.
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Hints:
1. Your functions in hmwk_05_imperative.java must be RECURSIVE!
Do not write the functions using iteration. Iterative
solutions will score ZERO points.
2. Your lambdas in hmwk_05_lambda.java must NOT use code
blocks. Code blocks are for more complex lambdas. Code
block solutions will score ZERO points.
3. As a reminder, in Java one can use System.out.format() to
print to the console.
4. These programs are not complex. Each of the three functions
in hmwk_05_imperative.java is THREE lines of code. The
lambdas in hmwk_05_lambda.java are THREE or FOUR lines
of code each.
Therefore, the total amount you have to write is about 20
lines of code.
5. Ensure your output messages match the contents of
‘outputdata.txt’. The output is going to be checked by a
program, so it has to match EXACTLY.
6. Ensure your programs compile and run correctly. Not
compiling or not generating the correct output will cost you
points.
After you write your programs, use diff or fc to compare
your output to the supplied ‘outputdata.txt’. It must match
EXACTLY or you will be penalized points.
(‘EXACTLY’ means character-by-character the same. No, e.g.,
differences in spacing, no changes in wording, no changes
in punctuation, no changes in capitalization, and so forth.
Check your output against the ‘outputdata.txt’ file!)
7. Ensure that you update the three header lines in each of the
source files with YOUR name (family name first, then a comma,
then your personal name), YOUR NetID, and the date you edit
the file.
Not updating the header lines properly will cost you points.
8. Ensure your submission to Blackboard is packaged EXACTLY as
described above.
— Your submission should be a ZIP FILE (not a tar, rar, gz,
or any other kind of compressed file).
— The zip file should be named ‘hmwk_05_abc1234.zip’ (with
‘abc1234’ replaced with YOUR NetID).
— This zip file should have ONE item in it, a directory
named ‘hmwk_05_abc1234’ (with ‘abc1234’ replaced with
YOUR NetID).
— Your source files should be in that directory. The
source files should be named hmwk_05_imperative.java
and hmwk_05_lambda.java.
Submissions in the wrong format score ZERO points.
9. After you submit your zip file on Blackboard, download it
from Blackboard and check that your submission is in the
proper format, that the programs run and print the correct
output, and that you updated the header lines correctly in
each of the source files.
10. Are you CERTAIN you complied with all of these nit-picking
instructions? Really? Maybe you ought to check just one
more time. 🙂
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