Doubly Linked List: Insert at End
#include<stdio.h>
#include<stdlib.h>
struct
node
{
int data;
struct node *llink;
struct node *rlink;
};
typedef
struct node* NODE;
NODE getnode();
NODE insert_at_end(NODE first, int
item);
void display(NODE first);
NODE
getnode()
{
NODE x;
x =(NODE) malloc(sizeof(struct node));
x->llink=NULL;
x->rlink=NULL;
return x;
}
void
display(NODE first)
{
NODE
cur;
cur
= first;
printf("\nContents
are:");
if(cur
== NULL)
printf("\nList
is empty. Nothing to display.");
else
{
while(cur!=NULL)
{
printf("%d ", cur->data);
cur
= cur->rlink;
}
}
}
NODE
insert_at_end(NODE first, int item)
{
int
val;
NODE
cur, temp;
temp
= getnode();
temp->data
= item;
if(first
== NULL) /*Case 1: List is empty*/
{
return
temp;
}
/*Case 2: List not empty. Update the link field of last node to point
to temp node.*/
cur
= first;
while(cur->rlink
!= NULL)
{
cur = cur->rlink;
}
cur->rlink = temp;
temp->llink = cur;
return
first;
}
void
main()
{
int
ch, item;
NODE
first = NULL;
while(1)
{
printf("\n\n~~MENU~~");
printf("\n1.Insert
at end");
printf("\n2.Display");
printf("\n3.exit");
printf("\nEnter
your choice: ");
scanf("%d",&ch);
switch(ch)
{
case 1: printf("\nEnter the value: ");
scanf("%d", &item);
first = insert_at_end(first, item);
break;
case
2: display(first);
break;
case
3: exit(0);
}
}
}
Output:
~~MENU~~
1.Insert
at end
2.Display
3.exit
Enter
your choice: 1
Enter the value: 11
~~MENU~~
1.Insert
at end
2.Display
3.exit
Enter
your choice: 1
Enter the value: 12
~~MENU~~
1.Insert
at end
2.Display
3.exit
Enter
your choice: 2
Contents are: 11 12
