#include<alloc.h>
struct list{
int data;
struct list *next;
}*head=NULL,*temp,*node;
void
laado(void),infirst(void), inpos(void), inlast(void), delfront(void),
delpos(void), dellast(void), display(void), count(void);
int
num,pos,empty(void);
char con;
int empty(void)
{
if(head==NULL)
{
clrscr();
printf("List is
empty!!!");
return 1;
}
else
return 0;
}
void main()
{
printf("\nMain
Menu\n1.Insert at first\n2.Insert at specified position\n3.Insert at
last\n4.Delete first\n5.Delete specified position\n6.Delete from
last\n7.Display\n8.Count number of nodes\n9.Exit\nEnter choice:");
scanf("%d",&num);
clrscr();
switch(num)
{
case 1:
infirst();
break;
case 2:
inpos();
break;
case 3:
inlast();
break;
case 4:
delfront();
break;
case 5:
delpos();
break;
case 6:
dellast();
break;
case 7:
display();
break;
case 8:
count();
break;
case 9:
clrscr();
exit();
case 45:
laado();
break;
default:
clrscr();
puts("\nWRONG
INPUT!!");
}
main();
}
void
infirst(void)
{
do
{
printf("Enter number:");
scanf("%d",&num);
if(head==NULL)
{
head=(struct
list*)malloc(sizeof(struct list));
head->data=num;
head->next=head;
}
else
{
temp=head;
while(temp->next!=head)
temp=temp->next;
node=(struct
list*)malloc(sizeof(struct list));
node->data=num;
node->next=head;
temp->next=node;
head=node;
}
printf("Continue
[y/n]?:");
con=getche();
}while(con=='y'||con=='Y');
}
void inpos(void)
{
do
{
num=0;
temp=head;
printf("Enter position to
insert at:");
scanf("%d",&pos);
while(temp->next!=head)
{
num++;
if(num==pos-1)
break;
temp=temp->next;
}
printf("Enter number:");
scanf("%d",&num);
node=(struct
list*)malloc(sizeof(struct list));
node->data=num;
node->next=temp->next;
temp->next=node;
printf("Continue
[y/n]?:");
con=getche();
} while(con=='y'||con=='Y');
}
void inlast(void)
{
do
{
printf("\nEnter number:");
scanf("%d",&num);
temp=head;
while(temp->next!=head)
temp=temp->next;
node=(struct list
*)malloc(sizeof(struct list));
node->data=num;
node->next=head;
temp->next=node;
printf("\nContinue
[y/n]?:");
con=getche();
} while(con=='y'||con=='Y');
}
void
delfront(void)
{
do
{
if(empty()==1) break;
else
{
temp=head;
while(temp->next!=head)
temp=temp->next;
if(temp==head)
{
free(head);
head=NULL;
}
else
{
temp->next=head->next;
free(head);
head=temp->next;
}
printf("Continue
[y/n]?:");
con=getche();
}
}while(con=='y'||con=='Y');
}
void delpos(void)
{
do
{
if(empty()==1) break;
if(head->next==head)
{
free(head);
head=NULL;
}
else
{
num=0;
temp=head;
printf("Enter
position:");
scanf("%d",&pos);
while(temp->next!=head)
{
num++;
if(num==pos-1)
break;
temp=temp->next;
}
node=temp->next->next;
free(temp->next);
temp->next=node;
printf("Continue
[y/n]?:");
con=getche();
}
}while(con=='y'||con=='Y');
}
void
dellast(void)
{
do
{
if(empty()==1) break;
else
{
temp=head;
while(temp->next!=head)
{
node=temp;
temp=temp->next;
}
if(temp==head)
{
free(head);
head=NULL;
}
else
{
node->next=head;
free(temp);
}
printf("Continue
[y/n]?:");
con=getche();
}
} while(con=='y'||con=='Y');
}
void
display(void)
{
if(empty()==1) return;
else
{
for(temp=head;temp->next!=head;temp=temp->next)
printf("%d
",temp->data);
printf("%d",temp->data);
}
}
void count(void)
{
if(empty()==1);
else
{
num=1;
temp=head;
while(temp->next!=head)
{
num++;
temp=temp->next;
}
printf("Total number of
nodes=%d",num);
}
}
void laado(void)
{
clrscr();
temp=head;
printf("Dynamic View of the
list:\n");
while(temp->next!=head)
{
printf("[%u|%d|%u]--->",temp,temp->data,temp->next);
temp=temp->next;
}
printf("[%u|%d|%u]",temp,temp->data,temp->next,head);
}
