Corning Community College
Project: DLL1
Errata
This section will document any updates applied to the project since original release:
Objective
In this project, we continue our doubly linked list re-write, completing the remaining library functions.
Procedure to Obtain dll1
As this project utilizes the code you wrote in dll0, you must upgrade to dll1 from dll0 (same thing that we did to transition between the sll* projects):
lab46:~/src/data/dll0$ make upgrade-dll1
...
Project Overview
As we started with the last project, we're implementing the remaining functions of our new doubly linked list implementation.
As such, new function prototypes have been added to the list.h header file:
code_t obtain (List **, Node **); // disconnect node from list
code_t empty (List **); // empty an existing list
code_t rmlist (List **); // deallocate empty list
code_t compare (List *, List *, ulli *); // compare two lists
code_t sortlist(List **, int); // sort list by mode
code_t swapnode(List **, Node *, Node *); // swap nodes in list
These functions will also make use of the status/error codes introduced in dll0. Additional effort has gone into identifying likely codes applied in various conditions. Be sure to reference the provided comments as well as the unit tests for more information.
The recommended order of implementation is:
obtain()
empty()
rmlist()
compare()
swapnode()
sortlist() (although note that sorting doesn't necessarily need swapping)
Implementing them out of order will likely result in unnecessary duplication of efforts, and I really don't want to see a half dozen half-baked obtain() implementations dribbled throughout your code.
list operation status codes
Just as with dll0, you'll notice the presence of a set of #define's in the data.h file. These are intended to be used to report on various states of list status after performing various operations.
They are not exclusive- in some cases, multiple states can be applied. The intent is that you will OR together all pertinent states and return that from the function.
DLL_SUCCESS - everything went according to plan, no errors encountered, average case
DLL_MALLOC_FAIL - memory allocation failed (considered in error)
DLL_ALREADY_ALLOC - memory has already been allocated (considered in error)
DLL_NULL - result is NULL (probably in error)
DLL_EMPTY - result is an empty list (may or may not be in error)
DLL_DEFAULT_FAIL - default state of unimplemented functions (default error)
DLL_ERROR - some error occurred
DLL_INVALID - invalid list condition
For example, in the case of “DLL_MALLOC_FAIL”, there are actually a total of three states raised:
DLL_ERROR (a problem has occurred)
DLL_MALLOC_FAIL (a problem has occurred when using malloc())
DLL_NULL (no memory allocated, so list cannot be anything but NULL)
ALL THREE states must be returned from the function in question should such an occurrence take place.
compare status codes
dll1 introduces additional status codes for one of its functions: compare()
Those codes are as follows:
//////////////////////////////////////////////////////////////////////
//
// Status codes for the doubly-linked list compare() function
//
#define CMP_EQUALITY 0x00
#define CMP_L1_NULL 0x01
#define CMP_L1_EMPTY 0x02
#define CMP_L1_UNDEFINED 0x03
#define CMP_L1_GREATER 0x04
#define CMP_L1_LESS 0x08
#define CMP_L2_NULL 0x10
#define CMP_L2_EMPTY 0x20
#define CMP_L2_UNDEFINED 0x30
#define CMP_L2_GREATER 0x40
#define CMP_L2_LESS 0x80
list library
In src/list/, you will find the addition of a new set of skeletons of the above prototyped functions, hollowed out in anticipation of being made operational.
Figure out what is going on, the connections, and make sure you understand it.
Be sure to focus on implementing the functionality from scratch (the more you do this from scratch, vs. referencing old code, the more it will help you).
List library unit tests
In unit/list/, you will find these new files:
unit-obtain.c - unit test for obtain() library function
unit-empty.c - unit test for empty() library function
unit-rmlist.c - unit test for rmlist() library function
unit-compare.c - unit test for compare() library function
unit-swap.c - unit test for swapnode() library function
unit-sort.c - unit test for sortlist() library function
Enhancements to these unit tests may be provided via dll1 project updates.
There are also corresponding verify-FUNCTION.sh scripts that will output a “MATCH”/“MISMATCH” to confirm overall conformance with the pertinent list functionality.
These are complete runnable programs (when compiled, and linked against the list library, which is all handled for you by the Makefile system in place).
Of particular importance, I want you to take a close look at:
Also note that, while considerable effort was made to ensure a broad range of tests were incorporated into each unit test, they are by no means a complete nor exhaustive battery of tests. There may be scenarios the unit tests do not currently check for. You are welcome and encouraged to perform additional tests to ensure your implementation is as rock solid as it can be.
List library applications
palindrome
Now that we've completed our doubly-linked list functionality, we can use these individual functions to piece together solutions to various everyday problems where a list could be effective. After all, that's a big aspect to learning data structures- they open doors to new algorithms and problem solving capabilities.
Our endeavor here will be to revisit that of palindromes (ie words/phrases that, when reversed, spell the same thing).
This implementation will be considered an extra credit opportunity, so as to offer those who have fallen behind (but working to get caught up) a reprieve on some of the credit they've lost.
It is also highly recommended to undertake as it will give you further experience working with these concepts.
Expected Results
To assist you in verifying a correct implementation, a fully working implementation of the node and list libraries should resemble the following (when running the respective verify script):
list library
Here is what you should get for list:
lab46:~/src/data/dll1$ make check
======================================================
= Verifying Doubly-Linked List Functionality =
======================================================
[obtain] Total: 57, Matches: 57, Mismatches: 0
[empty] Total: 7, Matches: 7, Mismatches: 0
[rmlist] Total: 7, Matches: 7, Mismatches: 0
[compare] Total: 12, Matches: 12, Mismatches: 0
[swapnode] Total: 31, Matches: 31, Mismatches: 0
[sortlist] Total: 48, Matches: 48, Mismatches: 0
======================================================
[RESULTS] Total: 162, Matches: 162, Mismatches: 0
======================================================
lab46:~/src/data/dll1$
Submission
Project Submission
When you are done with the project and are ready to submit it, you simply run make submit:
lab46:~/src/data/PROJECT$ make submit
...
Submission Criteria
To be successful in this project, the following criteria must be met:
Project must be submit on time, by the posted deadline.
Early submissions will earn 1 bonus point per full day in advance of the deadline.
Late submissions will lose 25% credit per day, with the submission window closing on the 4th day following the deadline.
To clarify: if a project is due on Wednesday (before its end), it would then be 25% off on Thursday, 50% off on Friday, 75% off on Saturday, and worth 0% once it becomes Sunday.
Certain projects may not have a late grace period, and the due date is the absolute end of things.
all requested functions must be implemented in the related library
all requested functionality must conform to stated requirements (either on this project page or in comment banner in source code files themselves).
Output generated must conform to any provided requirements and specifications (be it in writing or sample output)
Processing must be correct based on input given and output requested
Project header files are NOT to be altered. During evaluation the stock header files will be copied in, which could lead to compile-time problems.
Code must compile cleanly.
Code must be nicely and consistently indented (you may use the indent tool)
You are free to use your own coding style, but you must be consistent
Avoid unnecessary blank lines (some are good for readability, but do not go overboard- double-spacing your code will get points deducted).
Indentation will be rated on the following scale (worth 3 total points):
3/3: Aesthetically pleasing, pristine indentation, easy to read, organized
2/3: Mostly consistent indentation, but some distractions (superfluous or lacking blank lines, or some sort of “busy” ness to the code)
1/3: Some indentation issues, difficult to read
0/3: Lack of consistent indentation (didn't appear to try)
Unless fundamentally required, none of your code should perform any inventory or manual counting. Basing your algorithms off such fixed numbers complicates things, and is demonstrative of a more controlling nature.
Code must be commented
Any “to be implemented” comments MUST be removed
Commenting will be rated on the following scale (worth 3 total points):
3/3: Aesthetically pleasing (comments aligned or generally not distracting), easy to read, organized
2/3: Mostly consistent, some distractions or gaps in comments (not explaining important things)
1/3: Light commenting effort, not much time or energy appears to have been put in.
0/3: No original comments
should I deserve nice things, my terminal is usually 90 characters wide. So if you'd like to format your code not to exceed 90 character wide terminals (and avoid line wrapping comments), at least as reasonably as possible, those are two sure-fire ways of making a good impression on me with respect to code presentation and comments.
Sufficient comments explaining the point of provided logic MUST be present
Code must be appropriately modified
Appropriate modifications will be rated on the following scale (worth 3 total points):
3/3: Complete attention to detail, original-looking implementation- also is not unnecessarily reinventing existing functionality
2/3: Lacking some details (like variable initializations), but otherwise complete (still conforms, or conforms mostly to specifications), and reinvents some wheels
1/3: Incomplete implementation (typically lacking some obvious details/does not conform to specifications)
0/3: Incomplete implementation to the point of non-functionality (or was not started at all)
Implementation must be accurate with respect to the spirit/purpose of the project (if the focus is on exploring a certain algorithm to produce results, but you avoid the algorithm yet still produce the same results– that's what I'm talking about here).. worth 3 total points:
3/3: Implementation is in line with spirit of project
2/3: Some avoidance/shortcuts taken (note this does not mean optimization– you can optimize all you want, so long as it doesn't violate the spirit of the project).
1/3: Generally avoiding the spirit of the project (new, different things, resorting to old and familiar, despite it being against the directions)
0/3: entirely avoiding.
Error checking must be adequately and appropriately performed, according to the following scale (worth 3 total points):
3/3: Full and proper error checking performed for all reasonable cases, including queries for external resources and data.
2/3: Enough error checking performed to pass basic project requirements and work for most operational cases.
1/3: Minimal error checking, code is fragile (code may not work in full accordance with project requirements)
0/3: No error checking (code likely does not work in accordance with project requirements)
Any and all non-void functions written must have, at most, 1 return statement
Absolutely, positively NO (as in ZERO) use of goto statements.
Track/version the source code in a repository
Filling out any submit-time questionnaires
Submit a copy of your source code to me using the submit tool (make submit will do this) by the deadline.