a different linked list(like doubly)

[kalar]

Hello.
we have this struct and we must to make a linked list

struct node {
    char name[NAMESIZE];
    char phone[PHONESIZE];
    struct node *prevName;     // previous node alphabetically
    struct node *prevNumber;   // previous node sorted by numbers
    struct node *nextName;     // next node alphabetically
    struct node *nextNumber;   // next node sorted by numbers
} ;

As i can see i must make a linked list(like doubly but with 4 pointers) or two doubly linked lists:
1)one with prevName and nextName
2) and one with prevNumber and nextNumber
From these lists i will print the elements alphabetically or sorted by numbers
I believe that i must make ONE list such as:
malloc for the newnode and then just change the pointesr to be sorted
My problem is that i can't do this in one list.I don't know what i need(maybe 2 while loops for the pointers?) and i am confused.Please give any idea?
(if you want i can post the code to add a number in a doubly linked list sorted)

[weaknessforcats]

Where did this struct come from?? It is absolutely how you do not design a node for a linked list.

You
a) do not have the data and the next/prev pointer in the same struct
b) do not use multiple sets of next/prev pointers for various list sort sequences.

I can make a recommendation but I need to know about where this struct originated.

[kalar]

Where did this struct come from?? It is absolutely how you do not design a node for a linked list.

You
a) do not have the data and the next/prev pointer in the same struct
b) do not use multiple sets of next/prev pointers for various list sort sequences.

I can make a recommendation but I need to know about where this struct originated.

If i understand what you say( i don't speak very good english)
for a) why? in the struct i gave you there are in the same struct
for help i can give a skeleton in which you can make the programm
Any idea how to make it would be very helpfull

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
 
#define NAMESIZE 51
#define PHONESIZE 11
 
/************************** TYPES ****************************/
 
enum {INSERT=1, DEL_NAME, DEL_NUM, PR_NAME, PR_NUM, EXIT};
 
typedef struct node {
    char name[NAMESIZE];
    char phone[PHONESIZE];
    struct node *prevName;   
    struct node *prevNumber;   
    struct node *nextName;    
    struct node *nextNumber;  
} nodeT;
 
/************************** GLOBALS ***************************/
 
nodeT *root ;
 
/************************ PROTOTYPES  *************************/
void printByName () ;
void printByNumber () ;
void initialize() ;
void destroy() ;
int searchByName( char name[]) ;
int searchByNumber( char num[]) ;
int insert ( char name[], char num[]) ;
int removeName (char name[]) ;
int removeNumber(char num[]) ;
void print_menu() ;
 
/*************************** MAIN *****************************/
 
int main (int argc, char *argv[]) {
 
    int selection;
    char name[NAMESIZE];
    char last[NAMESIZE];
    char first[NAMESIZE];
    char num[PHONESIZE];
    int op_result;
    char dummy;
 
    initialize();
    do {
        print_menu();
        scanf("%d", &selection) ;
        scanf("%c", &dummy);
 
        switch(selection) {
            case INSERT:
                    break;
            case DEL_NAME:
                    break;
            case DEL_NUM:
                    break;
            case PR_NAME:
                    break;
            case PR_NUM:
                    break;
            case EXIT:
                    break;
        }
    } while (selection != EXIT);
    destroy();
    return 0;
}    
 
/************************** FUNCTIONS ****************************/

[kalar]

I can't edit my post so i post again

Am I in the right way if try to make it like a list or not?

[weaknessforcats]

I wanted to know if you are taking a class and you instructor said to use this struct, or have you just made it up yourself.

[kalar]

I wanted to know if you are taking a class and you instructor said to use this struct, or have you just made it up yourself.

yes i must use this struct, it is an exercise

[weaknessforcats]

OK. I just want you to know that this struct is not how you design a linked list.

That said, you should be able to use one list. But You will need two roots.
One for the squence by name and the other fof the seqence by phone number.

These roots should be local variable in main() rather than global variables. You pass them along as function arguments.

That implies two insert functions. One for the name sequence and one for the phone number sequence.

Then when you insert, say using the phone number sequence, from inside that function you have to also insert by name so all four pointers are correct.

This means the insert functions cannot create the node to be inserted. It will have to be passed in.

Both roots also need to be passed in.

Maybe:

int main()
{
    NodeT* listbyname = 0;
    NodeT* listbynumber = 0;
    NodeT* obj = CreateNode("John", "Frank", "Jones", "555-234-1345");
    insert(&listbyname, &listbynumber, obj);
}
 

In this way you can use whichever root to display the list in different sequences.

Again, I repeat, this is not how to do this in real life.

[kalar]

Thanks for your answer.I also think something like this that you suggest me but the function prototype for insert() has been given to me as :
int insert ( char name[], char num[]) ;

So i shouldn't pass to the function anything else.If i make root1 and root2 globals and a code like this i hope that i have the result i want.What's your opinion?(or we say the same things?)

int insert ( char name[], char num[]) {
 
struct node *newnode;
newnode = (struct node *)malloc(sizeof(struct node));
 
/*copy the data in the fields of newnode and then */
 
/*while loop to find the right position alphabetically*/
/*make the pointers*/
 
 
 
/*while loop to find the right position to be sorted by number*/
/*make the pointers*/
}

[Raghunandan24]

[quote=kalar]Hello.
we have this struct and we must to make a linked list

struct node {
    char name[NAMESIZE];
    char phone[PHONESIZE];
    struct node *prevName;     // previous node alphabetically
    struct node *prevNumber;   // previous node sorted by numbers
    struct node *nextName;     // next node alphabetically
    struct node *nextNumber;   // next node sorted by numbers
} ;

QUOTE]

As i see it you need to make two doubly linked lists. One for the names and one for the numbers.
Why do you have two arrays inside the structure? do you have to add all the array values to the linked lists?
To do this you need to create an instance of the structure in the main method.
Using
[code]
// create instance of structure in main method
instance -> data= <values>
instance -> next= <new instance> // this points to the next node
//Similarly you need to use ->prev to point to the previous instance.
[code]

Hope this helps

Raghu

[kalar]

Why do you have two arrays inside the structure? do you have to add all the array values to the linked lists?

Raghu

Thanks but i must use the struct as it is .I can't change the struct(as i say in another post it is an exercise)

[Raghunandan24]

Thanks but i must use the struct as it is .I can't change the struct(as i say in another post it is an exercise)

There must be some use of the two arrays in the structure. What are you trying to do with the arrays?

Tell me if you encounter any problems.

Raghu