Corning Community College
CSCS2320 Data Structures
~~TOC~~
This section will document any updates applied to the project since original release:
In this project, we take our first opportunity to undergo a complete code re-write of linked list functionality, while we implement our first doubly linked list.
As this is a rewrite, dll0 is not based on any of the code you have written up to this point. As such, the transition process is slightly different:
lab46:~/src/data/sll3$ make get-dll0 ...
The “get-” functionality is distinct from the “upgrade-” you have been using to transition between the sll* projects. When you upgrade, your existing code is copied over, because the next project builds upon what you did previously.
But when you “get” dll0, you are getting an entirely new project skeleton- NONE of your existing code is copied over (the structure has changed enough where copying your own code would have been rather problematic).
Once you run “make get-dll0” you should have a dll0 directory that you can access and commence working on just as you have with the other project directories.
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:
#ifndef _NODE_H #define _NODE_H #include <stdlib.h> struct node { char value; struct node *after; struct node *prior; }; typedef struct node Node; Node *mknode(char ); // allocate new node containing value Node *cpnode(Node *); // duplicate node Node *rmnode(Node *); // deallocate node #endif
There is an addition of a “prior” node pointer, to allow connections to our previous neighbors.
The node info element has been renamed to “value”, just to make sure you understand what is going on code-wise.
#ifndef _LIST_H #define _LIST_H #include "node.h" // list relies on node to work #define DLL_SUCCESS 0 #define DLL_MALLOC_FAIL 1 #define DLL_ALREADY_ALLOC 2 #define DLL_NULL 4 #define DLL_EMPTY 8 #define DLL_DEFAULT_FAIL 64 #define DLL_FAIL 128 struct list { Node *first; // pointer to start of list Node *last; // pointer to end of list }; typedef struct list List; // because we deserve nice things int mklist (List **); // create/allocate new list struct int cplist (List *, List **); // duplicate list contents int insert (List **, Node *, Node *); // add node before given node int append (List **, Node *, Node *); // add node after given node int display(List *, int); // display list from start to end int find (List *, int, Node **); // locate node containing value #endif
The following changes have taken place:
There is now a set of status/error codes that will be utilized as list function return values, so we can better report particular failures.
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.
For example, in the case of “DLL_MALLOC_FAIL”, there are actually a total of three states raised:
ALL THREE states must be returned from the function in question should such an occurrence take place.
In src/node/, you will find skeletons of what was previously there, ready for you to re-implement.
In src/list/, you will find the same- 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).
In testing/list/unit/, you will find these new files:
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:
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):
Here is what you should get for node:
lab46:~/src/data/dll0$ bin/verify-node.sh ==================================================== = Verifying Doubly-Linked Node Functionality = ==================================================== [mknode] Total: 5, Matches: 5, Mismatches: 0 [cpnode] Total: 6, Matches: 6, Mismatches: 0 [rmnode] Total: 2, Matches: 2, Mismatches: 0 ==================================================== [RESULTS] Total: 13, Matches: 13, Mismatches: 0 ==================================================== lab46:~/src/data/dll0$
Here is what you should get for list:
lab46:~/src/data/dll0$ bin/verify-list.sh ==================================================== = Verifying Doubly-Linked List Functionality = ==================================================== [mklist] Total: 11, Matches: 11, Mismatches: 0 [cplist] Total: 17, Matches: 17, Mismatches: 0 [append] Total: 22, Matches: 22, Mismatches: 0 [insert] Total: 22, Matches: 22, Mismatches: 0 [display] Total: 12, Matches: 12, Mismatches: 0 [find] Total: 28, Matches: 28, Mismatches: 0 ==================================================== [RESULTS] Total: 112, Matches: 112, Mismatches: 0 ==================================================== lab46:~/src/data/dll0$
To be successful in this project, the following criteria must be met: