/*Write a program to attach two singly linked lists
#include<stdio.h>
#include<conio.h>
struct node//declaration of node structure
{
int data;//DATA FIELD
struct node *next;
};
struct list//declaration of list structure
{
struct node *head;
};
/*initilisation of the list*/
void init(struct list *l)
{
l->head=NULL;
}
/*create the new node*/
int create(struct node *p, int data)
{
if(p==NULL)//IF THE LIST IS EMPTY
return 1;
else
{
/*ADJUST THE POINTERS*/
p->data=data;
p->next=NULL;
return 0;
}
}
/*for inserting the node*/
int insert(struct list *l,int data)
{
struct node *p,*q;
int x;
p=(struct node *)malloc(sizeof(struct node));//allocate memory to the new node
x=create(p,data);//call create function to create the new node
if(x)//if newnode couldn't be created
return x;
else if(l->head==NULL)//if the list is already empty
l->head=p;
else
{
q=l->head;
while(q->next!=NULL)//TILL THE END
q=q->next;
q->next=p;
}
return 0;
}
/*displays the list*/
int display(struct list *l)
{
struct node *q=l->head;
if(q==NULL)//if the list is empty
return 1;
else
{
printf("\n");
while(q!=NULL)//till the end
{
printf(" %d-> ",q->data);
q=q->next;
}
printf("NULL");
return 0;
}
}
/*attaches the second list to the first*/
int attach(struct list *l1,struct list *l2)
{
struct node *p;
p=l1->head;//p now points to first node
if((l1->head==NULL)&&(l2->head==NULL))
return 1;
else if(l1->head==NULL)
return 2;
else if(l2->head==NULL)
return 3;
else
{
while(p->next!=NULL)
{
p=p->next;
}
p->next=l2->head;
return 0;
}
}
//main function
int main()
{
int data,x,y,pos,ch;
struct list l1,l2;
/*declare the head pointers of two lists */
l1.head=NULL;
l2.head=NULL;
clrscr();//clears the user screen
do
{
printf("\n Enter the data in the first linked list(-1 to stop) : ");
scanf("%d",&data);
if(data==-1)
break;
x=insert(&l1,data);//function call
if(x)
printf("\n Node can not be inserted ");
}while(data!=-1);
printf("\n The first linked list is: ");
x=display(&l1);//function call
if(x)
printf("\n List is empty ");
do
{
printf("\n Enter the data in the second linked list(-1 to stop) : ");
scanf("%d",&data);
if(data==-1)
break;
x=insert(&l2,data);//function call
if(x)
printf("\n Node can not be inserted ");
}while(data!=-1);
printf("\n The second linked list is: ");
x=display(&l2);//function call
if(x)
printf("\n List is empty ");
y=attach(&l1,&l2);//function call[attaches list]
if(y==1)
printf("\n Lists are empty ");
else if(y==2)
{
printf("\n First list is empty ");
printf("\n The list after attachment is : ");
display(&l2);
}
else if(y==3)
{
printf("\n Second list is empty ");
printf("\n The list after attachment is : ");
display(&l1);
}
else
{
printf("\n The attached linked list is : ");
display(&l1);
}
/*free the memory occcupied by the linked lists*/
free(l1);
free(l2);
getch();
return 0;
}
/*
OUTPUT
Enter the data in the first linked list(-1 to stop) : 1
Enter the data in the first linked list(-1 to stop) : 2
Enter the data in the first linked list(-1 to stop) : 3
Enter the data in the first linked list(-1 to stop) : -1
The first linked list is:
1-> 2-> 3-> NULL
Enter the data in the second linked list(-1 to stop) : 4
Enter the data in the second linked list(-1 to stop) : 5
Enter the data in the second linked list(-1 to stop) : -1
The second linked list is:
4-> 5-> NULL
The attached linked list is :
1-> 2-> 3-> 4-> 5-> NULL
