Page 56 - Data Structures Interactive Book
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6.4 Types of Queues
Beyond the basic linear queue, several variations exist to address specific limitations
and extend functionality.
6.4.1 Circular Queue
A circular queue connects the rear back to the front, forming a circle. This design
solves the problem of wasted space in simple array queues by reusing freed positions. Circular
queues are efficient in memory utilization and are widely used in buffering systems.
6.4.2 Double-Ended Queue (Deque)
A deque allows insertion and deletion from both ends of the queue. This flexibility
makes it suitable for scenarios where tasks may need to be added or removed from either
side. Deques can function as both stacks and queues depending on usage.
6.4.3 Priority Queue
A priority queue assigns a priority to each element, and elements with higher priority
are dequeued before those with lower priority. This structure is essential in scheduling
algorithms, where urgent tasks must be handled before routine ones.
6.5 Applications in Computer Science
Queues are integral to many algorithms and systems because they model real-world
processes naturally.
• Process scheduling: Operating systems use queues to manage processes waiting for
CPU time, ensuring fairness and efficiency.
• Breadth-first search (BFS): Graph traversal algorithms rely on queues to explore nodes
level by level, making them essential in shortest path problems.
• Resource sharing: Queues manage tasks in printers, disk scheduling, and network
packet handling, ensuring orderly processing.
• Simulation systems: Queues model real-world scenarios like customer service lines,
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