[coolio2006]

I understand that. I know it's just 2 nodes behind, but in terms of making the code go 2 nodes behind, that's a little tricky. Technically, the user needs to enter the length of the node and the size of the longlink - so it could be 20 nodes and longlink is every 6.

[coolio2006]

Here is my code to make it better to understand (Hopefully)

node *newnode = current;
node *temp = current; 
node *start = current;
int number = 0;
int num = 0; 
for (int i = 1; i < length; i++) // this function is just ensuring the node before the deleted node points to 2 nodes in front 
{
temp = temp -> shortlink;
}



if (newnode -> num == x)
{
number = current -> longlink -> num; // here as you can see i want to store the longlink value of the deleted node into the variable number
current = current -> shortlink;
temp -> shortlink = start -> shortlink;
delete newnode;
length--;
}


else

while (newnode -> shortlink -> num != start -> num)
{
if (newnode -> shortlink -> num == x)
{
temp = newnode -> shortlink; 
number = temp -> longlink -> num; // here as you can see i want to store the longlink value of the deleted node into the variable number
newnode -> shortlink = newnode -> shortlink -> shortlink;
delete temp;
length--;
}
newnode = newnode -> shortlink;
}


if (newnode -> shortlink -> shortlink -> num == length && newnode -> shortlink -> num == x)
{
delete newnode -> shortlink -> shortlink;
newnode -> shortlink = start;
length--;
}






for (int z = 1; z < length; z++) // this function goes through each node to see if any of the long links are pointing to the deleted node
{
// if i put a cout statement exactly here to cout number - it recognises the number variable fine
if (longlinker -> longlink -> num == x) // if i've found it // once it looks into this if statement - number isn't recognised - why?
{
longlinker -> longlink -> num = number; // then i want to update the longlink of this which stores number 
}
else
{
longlinker = longlinker -> shortlink; // otherwise keep iterating
}
}

[coolio2006]

I'm really stuck now some of the long links of the nodes that were referncing to the delete node now have ridiculous long link numbers (like 14155566)

[coolio2006]

The problem i got now is the following, and i'd REALLY be grateful if someone could assist me with this. Lets say i have 6 nodes and the long link is 3, then 1 points to 2 and 4, 2 points to 3 and 5, 3 points to 4 and 6 etc .....
When i delete node 1 and 2, then nodes 4 and 5 are longlinking back to 0 (for some reason). Can someone help me please? Code is here:

node *newnode = current;
node *temp = current; 
node *start = current;
node *longlinker = current;
int number = 0; 


for (int i = 1; i < length; i++)
      {
      temp = temp -> shortlink;
      }

if (newnode -> num == x)
{
start = start -> shortlink;
number = current -> longlink -> num;
current = current -> shortlink;
temp -> shortlink = start; 
delete newnode;
length--;
cout << "longlink for 1 is"  << number << endl;
}
else

for (int p = 1 ; p < length; p++)
{
if (newnode -> shortlink -> num == x)
{
		temp = newnode -> shortlink;
		number = temp -> longlink -> num;
		newnode -> shortlink = newnode -> shortlink -> shortlink;
		delete temp;
		length--;
}

else 
newnode = newnode -> shortlink;
}

[shabbir]

Still I dont get what problem you are facing. Its just the delete of a node from a link list then I have already given a code snippet to achieve the same and you can customize it to add extra information like short link and long link. Mine is just a simple where only one pointer exists and thats short link according to your problem and that is the next node.

[coolio2006]

Your code works fine (the sample), but that's only because each node is only linked to it's next node. My scenario is a little more complicated. Lets take this for instance, a list of 6 nodes and longlinks of 3: so the design looks like the following:

1 ----> 2( shortlink) && 1 ----> 4(longlink)
2 ----> 3( shortlink) && 1 ----> 5(longlink)
3 ----> 4( shortlink) && 1 ----> 6(longlink)
4 ----> 5( shortlink) && 1 ----> 1(longlink)
5 ----> 6( shortlink) && 1 ----> 2(longlink)
6 ----> 1( shortlink) && 1 ----> 3(longlink)

Shortlinks are working fine. Now in that scenario, if i deleted node 1, that means nothing shall point to it . We must oberve though node 1 has a shortlink to 1 and a longlink to 4. Anyway, as you can see there, node 4 has a longlink to node 1, but node 1 is deleted, therefore this is wrong. So what i need to be able to do is, node 4 must point to the long link of the delete nodes long list. After deleting node 1, it should now look like




2 ----> 3( shortlink) && 1 ----> 5(longlink)
3 ----> 4( shortlink) && 1 ----> 6(longlink)
4 ----> 5( shortlink) && 1 ----> 4(longlink) ( 4's longlink must point to itself because 1's longlink was 4
5 ----> 6( shortlink) && 1 ----> 2(longlink)
6 ----> 2( shortlink) && 1 ----> 3(longlink) (notice 6's shortlink is now 2 - this works fine).


My output is giving me this:

2 ----> 3( shortlink) && 1 ----> 5(longlink)
3 ----> 4( shortlink) && 1 ----> 6(longlink)
4 ----> 5( shortlink) && 1 ----> 0(longlink) (this should not be pointing to 0, it should be 4)
5 ----> 6( shortlink) && 1 ----> 2(longlink)
6 ----> 2( shortlink) && 1 ----> 3(longlink)

Hopefully that clarifies my situation atm, and i'd really be grateful for some assistance.

[coolio2006]

Ok so it's all deleting the nodes fine and updating the links, except when i go to remove the 1st node - it has a problem. Could someone please examine what i'm doing wrong.

void ring::remove(int x)
{

node *newnode = current;
node *temp = current; 
node *start = current;
node *longlinker = NULL;
node *shortdata = current; // this references to the first deleted node and will need it for testing longlink functionality
int number = 0; 


for (int i = 1; i < length; i++) // this for loop is used for creating the short link - for .e.g if node 4 is deleted, then node 3 points to 5 and not 3
      {
      temp = temp -> shortlink;
      }

if (newnode -> num == x)
{
start = start -> shortlink;
//number = current -> num;
current = current -> shortlink;
//number = temp -> num; 
temp = start;
newnode = start;
length--;
}
else


for (int p = 1 ; p < length; p++)
{
if (newnode -> shortlink -> num == x)
	{
		temp = newnode -> shortlink;
 		number = temp -> shortlink -> num;
        	newnode -> shortlink = newnode -> shortlink -> shortlink;
            longlinker = newnode -> shortlink;
		//delete newnode;		
		length--;
	}
else 
newnode = newnode -> shortlink;
}

for (int y = 1; y <= length; y++)
{
if (longlinker -> longlink -> num == temp -> num)
{
longlinker -> longlink -> num = temp -> longlink -> num;
}
else
longlinker = longlinker -> shortlink;
}

}

[coolio2006]

Anyone?

[shabbir]

This sounds quite an interesting Linked list and so thought of programming it. Here is the code for you to see.

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

/*
 * Program for single linked list which inserts / deletes
 * data into linked list. The structure of linked list is 
 * complex. Instead of just having a link to the shortlink 
 * pointer it even stores a refernce to other link
 *
 *
 */

// Structure templates
struct list
{
    int no;
    struct list *shortlink;
    struct list *longlink;
};
typedef struct list node;

node *head = NULL;

void init(node*);
void InsertNode();
void DeleteNode();
void DisplayList();

void main()
{
    char ch = 'n';
    int opt;
    do
    {
        printf("\nEnter your option\n");
        printf("\n1. Insert a node\n");
        printf("\n2. Delete a particular node\n");
        printf("\n3. Display all the nodes\n");
        printf("\n4. Exit the application\n");
        scanf("%d",&opt);
        switch(opt)
        {
        case 1:
            InsertNode();
            DisplayList();
            break;
        case 2:
            DeleteNode();
            DisplayList();
            break;
        case 3:
            DisplayList();
            break;
        case 4:
            ch = 'y';
            break;
        }
    }while(ch != 'y');
    printf("\nDone by \"SHABBIR\"\n");
    getch();
}

void init(node *current)
{
    printf("\nEnter number\n");
    scanf("%d",&current->no);
    current->shortlink = NULL;
    current->longlink = NULL;
}

void InsertNode()
{
    node *newnode;
    
    newnode=(node*)malloc(sizeof(node));

    init(newnode);

    if(head == NULL)
    {
        head = newnode;
    }
    else
    {
        node *current = head;
        node *longlinkedNode = NULL;

        // Move to the end of the link list
        for(int i = 1; current->shortlink!=NULL ; i++)
        {
            if(i % 2 == 0)
            {
                longlinkedNode = current;
            }
            current=current->shortlink;
        }

        if(current->shortlink==NULL)
        {
            newnode->shortlink = current->shortlink;
            newnode->longlink = longlinkedNode;

            current->shortlink = newnode;
        }
    }
}

void DeleteNode()
{
    node* current = head;
    int rno;
    node *newnode,*temp;

    printf("\nEnter the number whose node you want to delete\n");
    scanf("%d",&rno);
    newnode=current;

    if(current->no==rno)
    {
        // Deleting the first node
        newnode=current;
        current=current->shortlink;
        free(newnode);
        head = current;
        return;
    }
    else
    {
        node* longlinkedNode = NULL;

        for(int i = 1; newnode->shortlink->shortlink!=NULL; i++)
        {
            if(i % 2 == 0)
            {
                longlinkedNode = current;
            }         // Checking condition for deletion of
            // all nodes except first and last node
            if(newnode->shortlink->no==rno)
            {
                temp=newnode->shortlink;
                newnode->shortlink=newnode->shortlink->shortlink;
                longlinkedNode->longlink = temp->longlink;
                free(temp);
                head = current;
                return;
            }
            newnode=newnode->shortlink;
        }
        if(newnode->shortlink->shortlink==NULL && newnode->shortlink->no==rno)
        {
            // Checking condition for deletion of last node
            free(newnode->shortlink);
            longlinkedNode->longlink = newnode->shortlink->longlink;
            newnode->shortlink=NULL;
            head = current;
            return;
        }
    }
}

void DisplayList()
{
    node* current = head;

    while(current!=NULL)
    {
        printf("\n %d ",current->no);
        current=current->shortlink;
    }
}

I dont think it was that different a code from what I have posted.

[anoop4real]

Hell o I am new member of this site. I am having some problems with linked lists. I want the solution for the problem described below can you help me with the code .
We have to open a new text file and do these operations in that
for eg:Name and mark of a student
Add Node .
Delete Node -
Insert Node - Same as Add Node, but takes an additional parameter of the location in which this new node is to be inserted
Sort Nodes -
Display Nodes - Should display the whole list in Name1 (mark), Name 2 (mark)... format.
Save Nodes - This will output the curent list and save it into the same mark.txt file
Exit - Exits the Application.
I need it on Wednesday