Queue Implementation Using Array & Linked List

1. Queue Implementation Using Arrays & Linked List BY : SADIA ZAR

2. Basic Operations Two Basic Operations in Queue Enque : Inserting new element from rear end Deque : Removing existing element from front end Front End Rear End 0 1 2 3 4 5 6

3. Queue Using Arrays #include <iostream> using namespace std; class Queue { int * array ,size,f,r,count; public: Queue(); void Enque( int value); int Deque(); bool is_Empty(); bool is_Full(); }; Inserts an element that is passed through main function Removes an element at front

4. Constructor Queue::Queue() { cout<< "Enter size : " ; cin>>size; array = new int [size]; f=r=-1; count=0; }

5. Enque void Queue::Enque( int value) { if (!is_Full()) { array [++r]=value; count++; } else { cout<< "\n\nOverFlow ! \n\n" ; } }

6. Deque int Queue::Deque() { if (!is_Empty()) { count--; return array [++f]; } else { cout<< "\n\nUnderFlow ! \n\n" ; } }

7. Overflow & Underflow bool Queue::is_Empty() { return f==r==-1; } bool Queue::is_Full() { return count==size; } Underflow Overflow

8. main function void main() { Queue obj; obj.Enque(1); obj.Enque(2); obj.Enque(3); obj.Deque(); } 1 2 3 0 1 2 3 4 5 6

9. Queue using Linked List

10. Abstract Class #include <iostream> using namespace std; class Node { int value; Node*next; friend class Queue; public: Node() { next=NULL; } };

11. Class & Functions Declaration class Queue { Node *first,*last; public: Queue() { first=last=NULL; } void Enque( int v); bool is_Empty(); void Deque(); void Display(); }; first last

12. Enque void Queue::Enque( int v) { Node *n= new Node(); n->value=v; if (first==NULL) { last=first=n; } else { last->next=n; last=n; } } DATA NEXT

13. Deque void Queue::Deque() { if (!is_Empty()) { Node *temp=first; first=first->next; cout <<"\n\nThe data Dequeued is : " <<temp->value<<endl; delete temp; } }

14. Function to check Queue empty or not bool Queue::is_Empty() { return first==NULL||last==NULL; } UNDERFLOW

15. Display void Queue::Display() { Node *p = new Node; p = first; cout<< "\n\nQueue Elements are : \n\n" ; while (p!=NULL) { cout <<p->value<<endl; p = p->next; } }

16. main function Void main() { Queue Q; Q.Enque(12); Q.Enque(15); Q. Deque(); Q .Display(); } 100 200 12 15 200 NULL 100 200 first last 200