======Linked List Program======

A project for DATA by Kyle Pryslopski Fall Semester 2011.

This project was begun on ? and is anticipated to take till 12/2. (Upon completion you can correct this with the actual length).

=====Objectives=====
State the purpose of this project. What is the point of this project? What do we hope to accomplish by undertaking it?

=====Prerequisites=====
In order to successfully accomplish/perform this project, the listed resources/experiences need to be consulted/achieved:

  * Matt
  * Joe
  * Karl
  * linked lists
  * character fuctions

=====Background=====


=====Scope=====
This project is to make a program that makes a list and edits it.

=====Attributes=====


=====Procedure=====
I made the separate programs then put them together to make the final program.

=====Code=====
<code c>

#include <stdio.h>
#include <stdlib.h>

struct node {
        int value;
        struct node *next;
        struct node *prev;
};
typedef struct node Node;

int main()
{
        int input, input2, i = 0;
        Node *start, *tmp, *tmp2, *end;

        start = tmp = NULL;

        printf("Enter a value (-1 to quit): ");
        scanf("%d", &input);

        do {

                if (input == -1)
                        break;

                if (start == NULL)
                {
                        start = (Node *) malloc (sizeof(Node));
                        start -> value = input;
                        start -> next = NULL;
                        tmp = start;
                        end = start;
                }
                else
                {
                        tmp -> next = (Node *) malloc (sizeof(Node));
                        tmp -> next -> value = input;
                        tmp -> next = (Node *) malloc (sizeof(Node));
                        tmp -> next -> value = input;
                        tmp -> next -> next = NULL;
                        tmp = tmp -> next;
                        end = end -> next;
                }

                printf("Enter a value (-1 to quit): ");
                scanf("%d", &input);

        } while (input != -1);

        tmp = start;

        while(tmp != NULL)
        {
                printf("[%d] value = %d\n", i, tmp -> value);
                tmp = tmp -> next;
                i++;
        }

        printf("Select a node to delete: ");
        scanf("%d", &input2);

        tmp = start;
        for(i=0; i<(input2-1); i++)
        {
                tmp = tmp -> next;
        }

        if ((tmp == start) && (input != 1))
        {
                start = start -> next;
                tmp -> next = NULL;
                free(tmp);
                tmp = NULL;
        }
        else
        {
                tmp2 = tmp -> next;
                tmp -> next = tmp2 -> next;
                tmp2 -> next = NULL;
                free(tmp2);
                tmp2 = NULL;
        }

        i = 0;
        tmp = start;

        while(tmp != NULL)
        {
                printf("[%d] value = %d\n", i, tmp -> value);
                tmp = tmp -> next;
                i++;
        }

        printf("Enter node to insert before: ");
        scanf("%d", &input);

        tmp = start;

        for(i=0; i<(input-1); i++)
        {
                tmp = tmp -> next;
        }

        printf("Enter a value: ");
        scanf("%d", &input2);

        tmp2 = (Node *) malloc (sizeof(Node));
        tmp2 -> value = input2;

        if((tmp == start) && (input != 1))
        {
                tmp2 -> next = start;
                start = tmp2;
        }
        else
        {
                tmp2 -> next = tmp -> next;
                tmp -> next = tmp2;
        }

        i = 0;
        tmp = start;

        while(tmp != NULL)
        {
                printf("[%d] value = %d\n", i, tmp -> value);
                tmp = tmp -> next;
                i++;
        }

        printf("Enter node to insert after: ");
        scanf("%d", &input);

        tmp = start;
        for(i=0; i<input; i++)
        {
                tmp = tmp -> next;
        }

        printf("Enter a value: ");
        scanf("%d", &input2);

        tmp2 = (Node *) malloc (sizeof(Node));
        tmp2 -> value = input2;
        if((tmp == end) && (input != 1))
        {
                tmp2 -> prev = end;
                end -> next = tmp2;
                end = end -> next;
        }
        else
        {
                tmp2 -> prev = tmp;
                tmp2 -> next = tmp -> next;
                tmp -> next = tmp2;
                tmp2 -> next -> prev = tmp2;
        }

        i = 0;
        tmp = start;

        while(tmp != NULL)
        {
                printf("[%d] value = %d\n", i, tmp -> value);
                tmp = tmp -> next;
                i++;
        }

        return(0);
}


</code>

=====Execution=====
Again, if there is associated code with the project, and you haven't already indicated how to run it, provide a sample run of your code:

<cli>
lab46:~/src/cprog/linkedA$ ./projecta
Enter a value (-1 to quit): 1
Enter a value (-1 to quit): 2
Enter a value (-1 to quit): 3
Enter a value (-1 to quit): 4
Enter a value (-1 to quit): 5
Enter a value (-1 to quit): -1
[0] value = 1
[1] value = 2
[2] value = 3
[3] value = 4
[4] value = 5
Select a node to delete: 2
[0] value = 1
[1] value = 2
[2] value = 4
[3] value = 5
Enter node to insert before: 2
Enter a value: 3
[0] value = 1
[1] value = 2
[2] value = 3
[3] value = 4
[4] value = 5
Enter node to insert after: 4
Enter a value: 6
[0] value = 1
[1] value = 2
[2] value = 3
[3] value = 4
[4] value = 5
[5] value = 6
lab46:~/src/cprog/linkedA$ 
</cli>

=====Reflection=====
This was a confusing program to make because the append function was not working.

=====References=====