#include<stdlib.h>
#include<stdio.h>
typedef struct Queue
{
int val;
struct Queue *next;
}qu;
qu *insert(qu* , int);
int dele(qu **);
int peek(qu *);
int isempty(qu *);
void disp(qu *);
int main()
{
qu *head=NULL;
int v,ch;
while(1)
{
printf("\n\n1) Insert \n\n2) Delete \n\n3) Peek \n\n4) Display \n\n5) Exit");
printf("\n\nEnter your choice : ");
scanf("%d",&ch);
switch(ch)
{
case 1: printf("\nEnter the value : ");
scanf("%d",&v);
head=insert(head,v);
break;
case 2: if(!isempty(head))
{
v=dele(&head);
printf("\nDeleted element is %d ",v);
}
else
printf("\nNo value in the queue");
break;
case 3: if(!isempty(head))
{
v=peek(head);
printf("\nFront element is %d ",v);
}
else
printf("\nNo value in the queue");
break;
case 4: if(!isempty(head))
{
printf("\nValues in the queue are : \n");
disp(head);
}
else
printf("\nNo value in the queue");
break;
case 5: exit(0);
default: printf("\nWrong Choice");
}
}
return 0;
}
qu *insert(qu *h,int g)
{
qu *ptr,*temp;
temp=(qu *)malloc(sizeof(qu));
temp->val=g;
temp->next=NULL;
if(h==NULL)
h=temp;
else
{
ptr=h;
while(ptr->next!=NULL)
{
ptr=ptr->next;
}
ptr->next=temp;
}
return h;
}
int dele(qu **h)
{
int m;
qu *temp;
temp=*h;
m=(*h)->val;
(*h)=(*h)->next;
free(temp);
return m;
}
int peek(qu *h)
{
return h->val;
}
int isempty(qu *h)
{
if(h==NULL)
return 1;
else
return 0;
}
void disp(qu *h)
{
qu *ptr;
ptr=h;
while(ptr!=NULL)
{
printf("|%3d|",ptr->val);
ptr=ptr->next;
}
}
