Hi ,all.Can someone please explain this source code with an example???
***********************************************************************
#include <stdio.h>
typedef struct list_tag {
int data;
struct list_tag *next;
}ListNode;
typedef ListNode *slist;
slist empty = NULL;
void slistInsert(slist *sp,int t)
{
ListNode *n=(ListNode *)malloc(sizeof(ListNode));
if(n == NULL)
{
printf("Out of memory\n");
exit(1);
}
n->data = t;
while(*sp!=NULL && (*sp)->data < t)
{
sp = &((*sp)->next); //Why we do this here,i miss this point
}
n->next = *sp;
*sp = n;
}
void slistRemove(slist *sp,int t)
{
ListNode *n;
while(*sp!=NULL && (*sp)->data <t)
sp = &((*sp)->next);
if(*sp == NULL)
{
printf("Not found\n");
exit(1);
}
n=*sp;
*sp = (*sp)->next;
free(n);
}
void slistPrint(slist s)
{
ListNode *n;
for(n=s;n!=NULL; n=n->next)
printf("%d\n",n->data);
}
void main()
{
slistInsert(&empty,4);
slistInsert(&empty,8);
slistInsert(&empty,24);
slistInsert(&empty,50);
slistInsert(&empty,20);
slistInsert(&empty,2);
slistRemove(&empty,4);
slistInsert(&empty,18);
slistPrint(empty);
}
Thank you very much in advance.
Nanakos Chrysostomos wrote:
>Hi ,all.Can someone please explain this source code with an example???
>
>
>
Homework?
>***********************************************************************
>#include <stdio.h>
>
>typedef struct list_tag {
> int data;
> struct list_tag *next;
>}ListNode;
>
>typedef ListNode *slist;
>slist empty = NULL;
>
>void slistInsert(slist *sp,int t)
>{
> ListNode *n=(ListNode *)malloc(sizeof(ListNode));
> if(n == NULL)
> {
> printf("Out of memory\n");
> exit(1);
> }
> n->data = t;
> while(*sp!=NULL && (*sp)->data < t)
> {
> sp = &((*sp)->next); //Why we do this here,i miss this point
> }
>
>
This is a _sorted_ list, right. So somehow we have to sort it.
What it does is to either find a node with a value higher then 't', or
it reach the end of the list. Meanwhile, it just continue walking the list.
> n->next = *sp;
> *sp = n;
>
>
... so here we hock the rest of the list with the new node.
>}
>
>
>void slistRemove(slist *sp,int t)
>{
> ListNode *n;
> while(*sp!=NULL && (*sp)->data <t)
> sp = &((*sp)->next);
> if(*sp == NULL)
> {
> printf("Not found\n");
> exit(1);
> }
>
> n=*sp;
> *sp = (*sp)->next;
> free(n);
>}
>
>void slistPrint(slist s)
>{
> ListNode *n;
> for(n=s;n!=NULL; n=n->next)
> printf("%d\n",n->data);
>}
>
>void main()
>{
>
>
>
NULL
> slistInsert(&empty,4);
>
>
4->NULL
> slistInsert(&empty,8);
>
>
4->8->NULL
> slistInsert(&empty,24);
>
4->8->24->NULL
> slistInsert(&empty,50);
>
>
4->8->24->50->NULL
> slistInsert(&empty,20);
>
>
4->8->20->24->50->NULL
> slistInsert(&empty,2);
>
>
2->4->8->20->24->50->NULL
> slistRemove(&empty,4);
>
>
Remove first value equal or more than 4.
2->8->20->24->50->NULL
> slistInsert(&empty,18);
>
>
2->8->18->20->24->50->NULL
> slistPrint(empty);
>
>
2
8
18
20
24
50
>}
>
>Thank you very much in advance.
>
>
cu
/Richard Knutsson
Nanakos Chrysostomos wrote:
> Hi ,all.Can someone please explain this source code with an example???
.....
> void slistInsert(slist *sp,int t)
> {
> ListNode *n=(ListNode *)malloc(sizeof(ListNode));
> if(n == NULL)
> {
> printf("Out of memory\n");
> exit(1);
> }
> n->data = t;
> while(*sp!=NULL && (*sp)->data < t)
> {
> sp = &((*sp)->next); // Why we do this here,i miss this point
This is done to move to the next item in the list.
The expression is complicated because 'sp' is a pointer to a pointer to
a structure.
> }
> n->next = *sp;
> *sp = n;
>
> }
>
.....
--
Matthijs Melchior.