#include<stdio.h>
#include<stdlib.h>
struct node
{
int info;
struct node *link;
};
struct node *createList(struct node *start);
void display(struct node *start);
void countNodes(struct node *start);
void search(struct node *start,int data);
struct node *insertInBeginning(struct node *start,int data);
struct node *insertAtEnd(struct node *start,int data);
struct node *insertAfter(struct node *start,int data,int item);
struct node *insertBefore(struct node *start,int data,int item );
struct node *insertAtPosition(struct node *start,int data,int pos);
struct node *deleteNode(struct node *start,int data);
struct node *reverseList(struct node *start);
main()
{
struct node *start=NULL;
int choice,data,item,pos;
while(1)
{
printf("1.Create List\n");
printf("2.Display\n");
printf("3.Count\n");
printf("4.Search\n");
printf("5.Add to empty list / Add at beginning\n");
printf("6.Add at end\n");
printf("7.Add after node\n");
printf("8.Add before node\n");
printf("9.Add at position\n");
printf("10.Delete\n");
printf("11.Reverse\n");
printf("12.Quit\n\n");
printf("Enter your choice : ");
scanf("%d",&choice);
switch(choice)
{
case 1:
start=createList(start);
break;
case 2:
display(start);
break;
case 3:
countNodes(start);
break;
case 4:
printf("Enter the element to be searched : ");
scanf("%d",&data);
search(start,data);
break;
case 5:
printf("Enter the element to be inserted : ");
scanf("%d",&data);
start=insertInBeginning(start,data);
break;
case 6:
printf("Enter the element to be inserted : ");
scanf("%d",&data);
start=insertAtEnd(start,data);
break;
case 7:
printf("Enter the element to be inserted : ");
scanf("%d",&data);
printf("Enter the element after which to insert : ");
scanf("%d",&item);
start=insertAfter(start,data,item);
break;
case 8:
printf("Enter the element to be inserted : ");
scanf("%d",&data);
printf("Enter the element before which to insert : ");
scanf("%d",&item);
start=insertBefore(start,data,item);
break;
case 9:
printf("Enter the element to be inserted : ");
scanf("%d",&data);
printf("Enter the position at which to insert : ");
scanf("%d",&pos);
start=insertAtPosition(start,data,pos);
break;
case 10:
printf("Enter the element to be deleted : ");
scanf("%d",&data);
start=deleteNode(start, data);
break;
case 11:
start=reverseList(start);
break;
case 12:
exit(1);
default:
printf("Wrong choice\n");
}/*End of switch */
}/*End of while */
}/*End of main()*/
struct node *createList(struct node *start)
{
int i,n,data;
printf("Enter the number of nodes : ");
scanf("%d",&n);
start=NULL;
if(n==0)
return start;
printf("Enter the element to be inserted : ");
scanf("%d",&data);
start=insertInBeginning(start,data);
for(i=2;i<=n;i++)
{
printf("Enter the element to be inserted : ");
scanf("%d",&data);
start=insertAtEnd(start,data);
}
return start;
}/*End of create_list()*/
void display(struct node *start)
{
struct node *p;
if(start==NULL)
{
printf("List is empty\n");
return;
}
p=start;
printf("List is :\n");
while(p!=NULL)
{
printf("%d ",p->info);
p=p->link;
}
printf("\n\n");
}/*End of display() */
void countNodes(struct node *start)
{
struct node *p;
int cnt=0;
p=start;
while(p!=NULL)
{
p=p->link;
cnt++;
}
printf("Number of elements are %d\n",cnt);
}/*End of countNodes() */
void search(struct node *start,int item)
{
struct node *p=start;
int pos=1;
while(p!=NULL)
{
if(p->info==item)
{
printf("Item %d found at position %d\n",item,pos);
return;
}
p=p->link;
pos++;
}
printf("Item %d not found in list\n",item);
}/*End of search()*/
struct node *insertInBeginning(struct node *start,int data)
{
struct node *tmp;
tmp=(struct node *)malloc(sizeof(struct node));
tmp->info=data;
tmp->link=start;
start=tmp;
return start;
}/*End of insertInBeginning()*/
struct node *insertAtEnd(struct node *start,int data)
{
struct node *p,*tmp;
tmp=(struct node *)malloc(sizeof(struct node));
tmp->info=data;
p=start;
while(p->link!=NULL)
p=p->link;
p->link=tmp;
tmp->link=NULL;
return start;
}/*End of insertAtEnd()*/
struct node *insertAfter(struct node *start,int data,int item)
{
struct node *tmp,*p;
p=start;
while(p!=NULL)
{
if(p->info==item)
{
tmp=(struct node *)malloc(sizeof(struct node));
tmp->info=data;
tmp->link=p->link;
p->link=tmp;
return start;
}
p=p->link;
}
printf("%d not present in the list\n",item);
return start;
}/*End of insertAfter()*/
struct node *insertBefore(struct node *start,int data,int item)
{
struct node *tmp,*p;
if(start==NULL )
{
printf("List is empty\n");
return start;
}
/*If data to be inserted before first node*/
if(item==start->info)
{
tmp=(struct node *)malloc(sizeof(struct node));
tmp->info=data;
tmp->link=start;
start=tmp;
return start;
}
p=start;
while(p->link!=NULL)
{
if(p->link->info==item)
{
tmp=(struct node *)malloc(sizeof(struct node));
tmp->info=data;
tmp->link=p->link;
p->link=tmp;
return start;
}
p=p->link;
}
printf("%d not present in the list\n",item);
return start;
}/*End of insertBefore()*/
struct node *insertAtPosition(struct node *start,int data,int pos)
{
struct node *tmp,*p;
int i;
tmp=(struct node *)malloc(sizeof(struct node));
tmp->info=data;
if(pos==1)
{
tmp->link=start;
start=tmp;
return start;
}
p=start;
for(i=1; i<pos-1 && p!=NULL; i++)
p=p->link;
if(p==NULL)
printf("There are less than %d elements\n",pos);
else
{
tmp->link=p->link;
p->link=tmp;
}
return start;
}/*End of insertAtPosition()*/
struct node *deleteNode(struct node *start,int data)
{
struct node *tmp,*p;
if(start==NULL)
{
printf("List is empty\n");
return start;
}
/*Deletion of first node*/
if(start->info==data)
{
tmp=start;
start=start->link;
free(tmp);
return start;
}
/*Deletion in between or at the end*/
p=start;
while(p->link!=NULL)
{
if(p->link->info==data)
{
tmp=p->link;
p->link=tmp->link;
free(tmp);
return start;
}
p=p->link;
}
printf("Element %d not found\n",data);
return start;
}/*End of deleteNode()*/
struct node *reverseList(struct node *start)
{
struct node *prev, *ptr, *next;
prev=NULL;
ptr=start;
while(ptr!=NULL)
{
next=ptr->link;
ptr->link=prev;
prev=ptr;
ptr=next;
}
start=prev;
return start;
}
