Linked_List

#include<stdio.h>
#include<malloc.h>
struct node {
int data;
struct node *next;
}*start;
void create(int d) {
struct node *q,*temp;
temp= (struct node* )malloc(sizeof(struct node));
temp->data=d;
temp->next=NULL;
if(start==NULL) /*If list is empty */
start=temp;
else { /*Element inserted at the end */
q=start;
while(q->next!=NULL)
q=q->next;
q->next=temp;
}
} //End of create()
void add_beg(int d) {
struct node *temp;
temp=(struct node* )malloc(sizeof(struct node));
temp->data=d;
temp->next=start;
start=temp;
}/*End of add_beg()*/
void add_after(int d,int pos) {
struct node *temp,*q;
int i;
q=start;
for(i=0;i<pos-1;i++) {
q=q->next;
if(q==NULL) {
printf("There are less than %d elements",pos);
return;
}
}
temp=(struct node* )malloc(sizeof(struct node) );
temp->next=q->next;
temp->data=d;
q->next=temp;
}//End of add_after()
void del(int d) {
struct node *temp,*q;
if(start->data == d) {
temp=start;
start=start->next; /*First element deleted*/
return;
}
q=start;
while(q->next->next != NULL) {
if(q->next->data==d) /*Element deleted in between*/
{
temp=q->next;
q->next=temp->next;
return;
}
q=q->next;
}/*End of while */
if(q->next->data==d) /*Last element deleted*/
{
temp=q->next;
q->next=NULL;
return;
}
printf("Element %d not found\n",d);
}//End of del()
void 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->data);
q=q->next;
}
printf("\n");
}//End of display()

void 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()

void main() {
int choice,n,e,position,i;
start=NULL;
while(1) {
printf("1.Create a linked 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.Quit\n");
printf("Enter your choice : ");
scanf("%d",&choice);
switch(choice) {
case 1:printf("How many nodes you want in the list: ");
scanf("%d",&n);
for(i=0;i<n;i++) {
printf("Enter the element : ");
scanf("%d",&e);
create(e);
}
break;
case 2:
printf("Enter the element : ");
scanf("%d",&e);
add_beg(e);
break;
case 3:
printf("Enter the element : ");
scanf("%d",&e);
printf("Enter the position after which this element is inserted : ");
scanf("%d",&position);
add_after(e,position);
break;
case 4:if(start==NULL)
{
printf("List is empty\n");
continue;
}
printf("Enter the element for deletion : ");
scanf("%d",&e);
del(e);
break;
case 5:display();
break;
case 6:count();
break;
case 7: exit(0);
default:
printf("Wrong choice\n");
} //End of switch
}//End of while
}//End of main()