queue using linkedlist Algorithm
queue supply services in computer science, transport, and operations research where various entity such as data, objects, persons, or events are stored and hold to be processed later. queue are common in computer programs, where they are implemented as data structures coupled with access routines, as an abstract data structure or in object-oriented languages as classes.
/*
Write a program to implement Queue using linkedlist.
*/
#include<iostream>
struct linkedlist{
int data;
linkedlist *next;
};
class stack_linkedList{
public:
linkedlist *front;
linkedlist *rear;
stack_linkedList(){
front=rear=NULL;
}
void enqueue(int);
int dequeue();
void display();
};
void stack_linkedList::enqueue(int ele){
linkedlist *temp=new linkedlist();
temp->data=ele;
temp->next=NULL;
if(front==NULL)
front=rear=temp;
else{
rear->next=temp;
rear=temp;
}
}
int stack_linkedList::dequeue(){
linkedlist *temp;
int ele;
if(front==NULL)
std::cout<<"\nStack is empty";
else{
temp=front;
ele=temp->data;
if(front==rear) //if length of queue is 1;
rear=rear->next;
front=front->next;
delete(temp);
}
return ele;
}
void stack_linkedList::display(){
if(front==NULL)
std::cout<<"\nStack is empty";
else {
linkedlist *temp;
temp=front;
while(temp!=NULL){
std::cout<<temp->data<<" ";
temp=temp->next;
}
}
}
int main(){
int op,data;
stack_linkedList ob;
std::cout<<"\n1. enqueue(Insertion) ";
std::cout<<"\n2. dequeue(Deletion)";
std::cout<<"\n3. Display";
std::cout<<"\n4. Exit";
while(1){
std::cout<<"\nEnter your choice ";
std::cin>>op;
if(op==1)
{
std::cout<<"Enter data ";
std::cin>>data;
ob.enqueue(data);
}
else if(op==2)
data=ob.dequeue();
else if(op==3)
ob.display();
else if(op==4)
exit(0);
else
std::cout<<"\nWrong choice ";
}
return 0;
}
