Adding nodes in the end of the list in C

[bflack]

Cn anybody give me a program about adding nodes at the end of the list in C?

I just need a basis of a program that I will be creating. I also needed its algorithm. Thanks in advance.

[N1GHTS]

Your question is incomplete. What list? What type? There are many types of lists.

[nbaztec]

Taking the list to be a singly ended.
1. Locate End Pointer (endPtr)
2. Create a new node (newPtr)
3. Initialize new node
4. Assign the link part of endPtr the address of newPtr
5. Make newPtr as new endPtr

[bflack]

Your question is incomplete. What list? What type? There are many types of lists.

What I mean is about SINGLY LINKED LIST in C programming.

[N1GHTS]

This issue is directly compatible with this issue on page 1 of the C forum.

http://www.daniweb.com/forums/thread313521.html

Maybe that could help.

[bflack]

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

struct node
{
    int num;
    struct node *next;
}               ;
typedef struct node nd;


main()
{
    int i, x;
    nd *head=NULL, *ptr;
    clrscr();
    head=malloc(sizeof(nd));
    ptr=head;
    printf("Enter numbers: ");
    for(i=0; i<5; i++)
    {
        scanf("%d", &x);
        while(ptr->next!=NULL)
        {
            ptr=ptr->next;
        }
        ptr->num=x;
        ptr->next=NULL;
    }

    ptr=head;
    printf("\n\nValues: ");
        for(i=0; i<5; i++)
    {
        if(ptr!=NULL)
        {
            printf("\n%d", ptr->num);
        }
    }

    getch;
}

Theres a logical error here but i can't find what it is. The problem is the output goes wrong when I print it. Cn anybody debug this program for me? pls

[N1GHTS]

while(ptr->next!=NULL)
{
   ptr=ptr->next;
}

ptr->next is uninitialized before this loop, so its never NULL, so it will run forever, since next contains garbage and will never be NULL.

[bflack]

I've modified that part and changed it to

while(ptr!=NULL)
{
ptr=ptr->next;
}

but still it doesn't print the right output?

[rajsekhar28]

Because you are initializing memory only once.Initialize memory whenever you add a new element.So dont initialize for the head in the start.Initialize memory after the while loop and also you can initialize the value at the same time.

[N1GHTS]

What I meant to say is that you don't have ptr->next=NULL before the while loop