Doubly Linked List to implement Insertions,Deletions,Traversal,Splitting,Merging,Counting Node & Sorting in C program.
CODING:
#include<stdio.h>
#include<conio.h>
struct node
{
struct node *next;
int data;
struct node *prev;
};
int flag=0;
struct node *splitlist;
struct node *start=NULL;
struct node *create(struct node *);
struct node *display(struct node *);
struct node *insert_beg(struct node *);
struct node *insert_before(struct node *start);
struct node *insert_node(struct node *start);
struct node *insert_after(struct node *start);
struct node *insert_end(struct node *);
struct node *delete_beg(struct node *);
struct node *delete_node(struct node *start);
struct node *delete_end(struct node *);
struct node *sort(struct node *);
struct node *split(struct node *);
struct node *merge(struct node *);
struct node *count_op(struct node *);
void main()
{
int ch;
clrscr();
printf("\nC R E A T E  THE LIST...");
start=create(start);
do
{
printf("\n -------------------------");
printf("\n| 1.OPEN THE LIST        |");
printf("\n| 2.ADD AT FIRST IN LIST |");
printf("\n| 3.BEFORE ADD   IN LIST |");
printf("\n| 4.ADD AT GIVEN POSITION|");
printf("\n| 5.AFTER  ADD   IN LIST |");
printf("\n| 6.ADD AT LAST  IN LIST |");
printf("\n| 7.DELETE FIRST IN LIST |");
printf("\n| 8.DELETE GIVEN IN LIST |");
printf("\n| 9.DELETE LAST  IN LIST |");
printf("\n|10.SORTING      IN LIST |");
printf("\n|11.SPLINTING    IN LIST |");
printf("\n|12:MERGING      IN LIST |");
printf("\n|13.COUNTING  OPERATIONS |");
printf("\n| 0.EXIT                 |");
printf("\n -------------------------");
printf("\nENTER THE CHOICE:");
scanf("%d",&ch);
switch(ch)
{
 case 1:
 start=display(start);
 break;
 case 2:
 start=insert_beg(start);
 printf("\n->First Record Added.");
 break;
 case 3:
 start=insert_before(start);
 printf("\n->Before Record Added.");
 break;
 case 4:
 start=insert_node(start);
 printf("\n->Record Added.");
 break;
 case 5:
 start=insert_after(start);
 printf("\n->After Record Added.");
 break;
 case 6:
 start=insert_end(start);
 printf("\n->Last Record Added.");
 break;
 case 7:
 start=delete_beg(start);
 printf("\n->First Record Deleted.");
 break;
 case 8:
 start=delete_node(start);
 printf("\n->Record Deleted.");
 break;
 case 9:
 start=delete_end(start);
 printf("\n->Last Record Deleted.");
 break;
 case 10:
 start=sort(start);
 printf("\n->Your List is Soretd.");
 break;
 case 11:
 start=split(start);
 break;
 case 12:
 start=merge(start);
 break;
 case 13:
 start=count_op(start);
 break;
 case 0:
 exit(0);
 break;
 default:
 printf("->INVALID ENTER NUMBER,TRY AGAIN!");
}
}while(ch!=0);
getch();
}
struct node *create(struct node *start)
{
struct node *new_node;
int num,n;
printf("\nHOW MANY ENTER THE RECORD IN LIST:");
scanf("%d",&n);
do
{
printf("Enter the number:");
scanf("%d",&num);
 if(start==NULL)
 {
  start=(struct node *)malloc(sizeof(struct node *));
  start->prev=NULL;
  start->data=num;
  start->next=NULL;
  n--;
 }
 else
 {
  new_node=(struct node *)malloc(sizeof(struct node *));
  new_node->prev=NULL;
  new_node->data=num;
  new_node->next=start;
  start->prev=new_node;
  start=new_node;
  n--;
 }
}while(0<n);
printf("->Your List Saved.");
return start;
}
struct node *display(struct node *start)
{
struct node *ptr;
ptr=start;
printf("LIST OPEN...");
while(ptr!=NULL)
{
 printf("\n%d",ptr->data);
 ptr=ptr->next;
}
if(flag==1)
{
ptr=splitlist;
printf("\n->SPLITTED LIST.");
while(ptr!=NULL)
 {
 printf("\n %d",ptr->data);
 ptr=ptr->next;
 }
printf("\n->ADD,DELETE,SORT ARE NOT WORK IN 'SPLITTED LIST'.");
}
return start;
}
struct node *insert_beg(struct node *start)
{
struct node *new_node;
int num;
printf("Enter The Number:");
scanf("%d",&num);
new_node=(struct node *)malloc(sizeof(struct node *));
start->prev=new_node;
new_node->prev=NULL;
new_node->data=num;
new_node->next=start;
start=new_node;
return start;
}
struct node *insert_before(struct node *start)
{
struct node *new_node,*ptr;
int num,n;
ptr=start;
printf("\nEnter The Before Number of Added In List:");
scanf("%d",&n);
if(ptr->data==n)
{
start=insert_beg(start);
}
else
{
printf("Enter The Number:");
scanf("%d",&num);
new_node=(struct node *)malloc(sizeof(struct node *));
new_node->data=num;
while(ptr->data!=n)
ptr=ptr->next;
new_node->next=ptr;
ptr->prev->next=new_node;
ptr->prev=new_node;
}
return start;
}
struct node *insert_node(struct node *start)
{
struct node *new_node,*ptr;
int num,n;
ptr=start;
printf("Enter The Position You Want To Added:");
scanf("%d",&n);
if(n==1)
{
start=insert_beg(start);
}
else
{
printf("Enter The Number:");
scanf("%d",&num);
new_node=(struct node *)malloc(sizeof(struct node *));
new_node->data=num;
while(2<n)
{
 ptr=ptr->next;
 n--;
}
new_node->prev=ptr;
new_node->next=ptr->next;
ptr->next->prev=new_node;
ptr->next=new_node;
}
return start;
}
struct node *insert_after(struct node *start)
{
struct node *new_node,*ptr;
int num,n;
printf("Enter The Number:");
scanf("%d",&num);
printf("\nEnter The After Number of Added In List:");
scanf("%d",&n);
new_node=(struct node *)malloc(sizeof(struct node *));
new_node->data=num;
ptr=start;
while(ptr->data!=n)
ptr=ptr->next;
new_node->prev=ptr;
new_node->next=ptr->next;
ptr->next->prev=new_node;
ptr->next=new_node;
return start;
}
struct node *insert_end(struct node *start)
{
int num;
struct node *ptr,*new_node;
ptr=start;
printf("Enter The Number:");
scanf("%d",&num);
new_node=(struct node *)malloc(sizeof(struct node *));
new_node->data=num;
while(ptr->next!=NULL)
ptr=ptr->next;
ptr->next=new_node;
new_node->next=NULL;
return start;
}
struct node *delete_beg(struct node *start)
{
struct node *ptr;
ptr=start;
start=start->next;
free(ptr);
return start;
}
struct node *delete_node(struct node *start)
{
struct node *ptr,*preptr;
int num;
printf("Enter The Number:");
scanf("%d",&num);
ptr=start;
if(ptr->data==num)
{
 start=delete_beg(start);
 return start;
}
else
 while(ptr->data!=num)
 {
 preptr=ptr;
 ptr=ptr->next;
 }
preptr->next=ptr->next;
free(ptr);
return start;
}
struct node *delete_end(struct node *start)
{
struct node *ptr,*preptr;
ptr=start;
while(ptr->next!=NULL)
{
 preptr=ptr;
 ptr=ptr->next;
}
preptr->next=NULL;
free(ptr);
return start;
}
struct node *sort(struct node *start)
{
struct node *ptr1,*ptr2;
int temp;
ptr1=start;
while(ptr1->next!=NULL)
{
 ptr2=ptr1->next;
 while(ptr2!=NULL)
 {
  if(ptr1->data>ptr2->data)
  {
   temp=ptr1->data;
   ptr1->data=ptr2->data;
   ptr2->data=temp;
  }
   ptr2=ptr2->next;
 }
ptr1=ptr1->next;
}
return start;
}
struct node *split(struct node *start)
{
int i;
struct node *s;
if(flag==0)
{
printf("Enter The Position of Split:");
scanf("%d",&i);
s=start;
while(i>1)
{
s=s->next;
i--;
}
splitlist=s->next;
splitlist->prev=NULL;
s->next=NULL;
s=start;
flag=1;
printf("\n->Your List is Splitted.");
}
else{printf("SORRY,Your List is Already Splitted");}
return start;
}
struct node *merge(struct node *start)
{
struct node *ptr;
ptr=start;
if(flag==0)
{
printf("SORRY,You have note Splitted List.");
}
else
{
while(ptr->next!=NULL)
ptr=ptr->next;
ptr->next=splitlist;
splitlist->prev=ptr;
flag=0;
printf("->Your List Merged.");
}
return start;
}
struct node *count_op(struct node *start)
{
struct node *ptr;
int odd=0,even=0,count=0;
ptr=start;
while(ptr!=NULL)
 {
  if(ptr->data%2==0)
   {
    printf("\nEVEN:%d",ptr->data);even++;
   }
  else
   {
    printf("\nODD :%d",ptr->data);odd++;
   }
 ptr=ptr->next;
 count++;
 }
printf("\nEVEN  Number of Nodes:%d",even);
printf("\nODD   Number of Nodes:%d",odd);
printf("\nTotal Number Of Nodes:%d",count);
return start;
}