Dynamically linked queues
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This document describes dynamically linked queues. It defines a Queue class with an item and link field. It shows how to add an item to the rear of the queue by creating a new Queue node, linking it to the current rear, and updating the rear pointer. It also shows how to delete from the rear by getting the front node, returning its item, and updating front to the next node. Diagrams illustrate the queue changes during add and delete operations.
![Dynamically Linked Queues
• Linked Queue
int MAX_QUEUES 10; /* maximum number of stacks */
Class Queue{
element item;
Queue link;
}
Queue front[MAX_QUEUES], rear[MAX_QUEUES];](https://image.slidesharecdn.com/dynamicallylinkedqueues-131215090255-phpapp02/85/Dynamically-linked-queues-2-320.jpg)
Dynamically linked queues
- 1. Dynamically Linked Queues Steve Paks
- 2. Dynamically Linked Queues • Linked Queue int MAX_QUEUES 10; /* maximum number of stacks */ Class Queue{ element item; Queue link; } Queue front[MAX_QUEUES], rear[MAX_QUEUES];
- 3. Dynamically Linked Queues(Cont’d) • Add to the rear of a linked queue void addq(Element item){ Queue temp = new Queue(); if(IS_FULL(temp)){ print(“The memory is full”); exit(1); } temp.item = item; temp.link = null; if(front != null) { rear.link = temp; ∙∙∙∙ (a) } else { front = temp; ∙∙∙∙ (b) } rear = temp; }
- 4. Dynamically Linked Queues(Cont’d) • Add to the rear of a linked queue(Cont’d) (a) item front (b) item front(=rear=temp) rear(=temp)
- 5. Dynamically Linked Queues(Cont’d) • delete from the rear of a linked queue Element deleteq(){ Queue temp = front; ∙∙∙∙ (a) Element item; if(IS_EMPTY(front)){ print(“The queue is empty?”); exit(1); } item = temp.item; ∙∙∙∙ (b) front = temp.link; ∙∙∙∙ (c) return item; }
- 6. Dynamically Linked Queues(Cont’d) • delete from the rear of a linked queue(Cont’d) (a) front(=temp) (b) rear a front rear a item (c) a front(=temp.link) rear