Table of Contents
Corning Community College
CSCS2320 Data Structures
Project: DLL0
Errata
This section will document any updates applied to the project since original release:
- revision #: <description> (DATESTAMP)
Objective
In this project, we continue our doubly-linked code re-write, this time focusing on the linked list.
Procedure to obtain dll0
As dll0 utilizes the code generated in dln0, transitioning to this project is merely a matter of upgrading:
lab46:~/src/data/dln0$ make upgrade-dll0 ...
When you upgrade, your existing code is copied over, because the next project builds upon what you did previously.
Once you run “make upgrade-dll0” you should have a dll0 directory that you can access and commence working on just as you have with the other project directories.
Project Overview
For this project, we're going to be re-implementing MOST of the previous node and list functions. There have been a few changes, namely:
In inc/list.h
- 1
#ifndef _LIST_H #define _LIST_H #include "node.h" // list relies on node to work struct list { Node *lead; // pointer to start of list Node *last; // pointer to end of list }; code_t mklist (List **); // create new list struct code_t cplist (List *, List **); // duplicate list contents code_t insert (List **, Node *, Node *); // add node before given node code_t append (List **, Node *, Node *); // add node after given node code_t display(List *, int); // display list start to end code_t find (List *, char, Node **); // locate node with value #endif
The following changes have taken place from the singly-linked list implementation:
- qty has been removed from the list (NO COUNTING!)
- getpos()/setpos() are no longer present. In many ways their functionality is no longer needed with the doubly-linked nature of the list (DO NOT RECREATE THEM NOR THEIR FUNCTIONALITY!)
- searchlist() has been renamed to find() (aesthetic change, to keep function names at 8 characters or less, and now supports resuming (finding additional matches).
- displayf()/displayb() are gone, and previous functionality will be merged into one universal display() function.
Just as with the doubly-linked node, there are now a set of status/error codes that will be utilized as list function return values, so we can better report particular failures.
In inc/data.h
In addition to what was there previously, we see the following:
- 1
////////////////////////////////////////////////////////////////////// // // Status codes for the doubly linked list implementation // #define DLL_SUCCESS 0x0000000000010000 #define DLL_MALLOC_FAIL 0x0000000000020000 #define DLL_ALREADY_ALLOC 0x0000000000040000 #define DLL_NULL 0x0000000000080000 #define DLL_ERROR 0x0000000000100000 #define DLL_EMPTY 0x0000000000200000 #define DLL_INVALID 0x0000000000400000 #define DLL_DEFAULT_FAIL 0x0000000000800000 ////////////////////////////////////////////////////////////////////// // // Options for list display() and support catlist() functions // #define DISPLAY_FORWARD 000 #define DISPLAY_NOPOSVALS 000 #define DISPLAY_POSVALS 001 #define DISPLAY_BACKWARD 002
Similar in many ways to the doubly-linked node status codes, we see a new possibility: EMPTY. This is the state of a list existing but having no nodes associated with it (which you should already be familiar with). Whenever this state exists, that status code MUST be set in the respective function being called (i.e. the list as a result of the function processing leaves us with an empty list).
list operation status codes
You'll notice the presence of a set of #define's in the list header 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 use (passing a NULL pointer)
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.
list library
In src/list/, you will find 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-mklist.c - unit test for mklist() library function
- unit-cplist.c - unit test for cplist() library function
- unit-append.c - unit test for append() library function
- unit-insert.c - unit test for insert() library function
- unit-find.c - unit test for find() library function
- unit-display.c - unit test for display() library function
Enhancements to these unit tests may be provided via dll0 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:
- the source code to each of these unit tests
- the purpose of these programs is to validate the correct functionality of the respective library functions
- follow the logic
- make sure you understand what is going on
- ask questions to get clarification!
- the output from these programs once compiled and ran
- analyze the output
- make sure you understand what is going on
- ask questions to get clarification!
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/dll0$ bin/verify-list.sh ====================================================== = Verifying Doubly-Linked List Functionality = ====================================================== [mklist] Total: 12, Matches: 12, Mismatches: 0 [cplist] Total: 18, Matches: 18, Mismatches: 0 [append] Total: 36, Matches: 36, Mismatches: 0 [insert] Total: 36, Matches: 36, Mismatches: 0 [display] Total: 12, Matches: 12, Mismatches: 0 [find] Total: 28, Matches: 28, Mismatches: 0 ====================================================== [RESULTS] Total: 142, Matches: 142, Mismatches: 0 ====================================================== lab46:~/src/data/dll0$
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.
- Bonus eligibility requires an honest attempt at performing the project (no blank efforts accepted)
- Late submissions will lose 33% credit per day, with the submission window closing on the 3rd day following the deadline.
- To clarify: if a project is due on Wednesday (before its end), it would then be 33% off on Thursday, 66% off on Friday, and worth 0% once it becomes Saturday.
- 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)
- output obviously must also be correct based on input.
- 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.
- Each source file must compile cleanly (worth 3 total points):
- 3/3: no compiler warnings, notes or errors.
- 2/3: one of warning or note present during compile
- 1/3: two of warning or note present during compile
- 0/3: compiler errors present (code doesn't compile)
- 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
- these “to be implemented” comments, if still present at evaluation time, will result in points being deducted.
- 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 exactly 1 return statement
- points will be lost for solutions containing multiple return statements in a function.
- Absolutely, positively NO (as in ZERO) use of goto statements.
- points will most definitely be lest for solutions employing such things.
- No custom global variables! The header files provide all you need.
- Do NOT edit the header files.
- 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.