Thanx a lot !!!!
On Mon, Aug 1, 2011 at 6:32 PM, Amethy hobby <[email protected]> wrote:
> if(start==NULL)
> {
> tmp->prev=NULL;
> // run here , the start==null, so the start->prev is error
> start->prev=tmp;//here
>
> start=tmp;
> }
>
> On 8月1日, 下午8时41分, Rajesh Kumar <[email protected]> wrote:
> > programs gives segmentation fault when we creat linked list
> > plz help me
> >
> > #include<stdio.h>
> > #include<malloc.h>
> > #include<stdlib.h>
> > struct node
> > {
> > struct node *prev;
> > int info;
> > struct node *next;
> >
> > }*start;
> >
> > main()
> > {
> > int choice,n,m,po,i;
> > start=NULL;
> > while(1)
> > {
> > printf("1.Create List\n");
> > printf("2.Add at begining\n");
> > printf("3.Add after\n");
> > printf("4.Delete\n");
> > printf("5.Display\n");
> > printf("6.Count\n");
> > printf("7.Reverse\n");
> > printf("8.exit\n");
> > printf("Enter your choice : ");
> > scanf("%d",&choice);
> > switch(choice)
> > {
> > case 1:
> > printf("How many nodes you want : ");
> > scanf("%d",&n);
> > for(i=0;i<n;i++)
> > {
> > printf("Enter the element : ");
> > scanf("%d",&m);
> > create_list(m);
> > }
> > break;
> > case 2:
> > printf("Enter the element : ");
> > scanf("%d",&m);
> > addatbeg(m);
> > break;
> > case 3:
> > printf("Enter the element : ");
> > scanf("%d",&m);
> > printf("Enter the position after which this element is
> inserted
> > : ");
> > scanf("%d",&po);
> > addafter(m,po);
> > break;
> > case 4:
> > printf("Enter the element for deletion : ");
> > scanf("%d",&m);
> > del(m);
> > break;
> > case 5:
> > display();
> > break;
> > case 6:
> > count();
> > break;
> > case 7:
> > rev();
> > break;
> > case 8:
> > exit(1);
> > default:
> > printf("Wrong choice\n");
> > }/*End of switch*/
> > }/*End of while*/
> >
> > }/*End of main()*/
> >
> > create_list(int num)
> > {
> > struct node *q,*tmp;
> > tmp= malloc(sizeof(struct node));
> > tmp->info=num;
> > tmp->next=NULL;
> > if(start==NULL)
> > {
> > tmp->prev=NULL;
> > start->prev=tmp;
> > start=tmp;
> > }
> > else
> > {
> > q=start;
> > while(q->next!=NULL)
> > q=q->next;
> > q->next=tmp;
> > tmp->prev=q;
> > }
> >
> > }/*End of create_list()*/
> >
> > addatbeg(int num)
> > {
> > struct node *tmp;
> > tmp=malloc(sizeof(struct node));
> > tmp->prev=NULL;
> > tmp->info=num;
> > tmp->next=start;
> > start->prev=tmp;
> > start=tmp;
> >
> > }/*End of addatbeg()*/
> >
> > addafter(int num,int c)
> > {
> > struct node *tmp,*q;
> > int i;
> > q=start;
> > for(i=0;i<c-1;i++)
> > {
> > q=q->next;
> > if(q==NULL)
> > {
> > printf("There are less than %d elements\n",c);
> > return;
> > }
> > }
> > tmp=malloc(sizeof(struct node));
> > tmp->info=num;
> > q->next->prev=tmp;
> > tmp->next=q->next;
> > tmp->prev=q;
> > q->next=tmp;
> >
> > }/*End of addafter() */
> >
> > del(int num)
> > {
> > struct node *tmp,*q;
> > tmp=malloc(sizeof(struct node));
> > if(start->info==num)
> > {
> > tmp=start;
> > start=start->next; /*first element deleted*/
> > start->prev = NULL;
> > free(tmp);
> > return;
> > }
> > q=start;
> > while(q->next->next!=NULL)
> > {
> > if(q->next->info==num) /*Element deleted in between*/
> > {
> > tmp=q->next;
> > q->next=tmp->next;
> > tmp->next->prev=q;
> > free(tmp);
> > return;
> > }
> > q=q->next;
> > }
> > if(q->next->info==num) /*last element deleted*/
> > { tmp=q->next;
> > free(tmp);
> > q->next=NULL;
> > return;
> > }
> > printf("Element %d not found\n",num);
> >
> > }/*End of del()*/
> >
> > display()
> > {
> > struct node *q;
> > if(start==NULL)
> > {
> > printf("List is empty\n");
> > return;
> > }
> > q=start;
> > printf("List is :\n");
> > while(q!=NULL)
> > {
> > printf("%d ", q->info);
> > q=q->next;
> > }
> > printf("\n");
> >
> > }/*End of display() */
> >
> > count()
> > { struct node *q=start;
> > int cnt=0;
> > while(q!=NULL)
> > {
> > q=q->next;
> > cnt++;
> > }
> > printf("Number of elements are %d\n",cnt);
> >
> > }/*End of count()*/
> >
> > rev()
> > {
> > struct node *p1,*p2;
> > p1=start;
> > p2=p1->next;
> > p1->next=NULL;
> > p1->prev=p2;
> > while(p2!=NULL)
> > {
> > p2->prev=p2->next;
> > p2->next=p1;
> > p1=p2;
> > p2=p2->prev; /*next of p2 changed to prev */
> > }
> > start=p1;
> >
> > }/*End of rev()*/
> >
> > --
> > Regards
> > Rajesh Kumar
>
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--
Regards
Rajesh Kumar
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