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Queues. Using arrays... Can populate an array with information... Then remove it as we deal with it. Queues. Have 2 functions... Store data to a queue... Deal with the data in the queue. Examples. Tasks queued by the OS, (Disk Access) Orders queued by a shop Hospital A&E Printer Queue.
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Queues • Using arrays... • Can populate an array with information... • Then remove it as we deal with it...
Queues • Have 2 functions... • Store data to a queue... • Deal with the data in the queue
Examples • Tasks queued by the OS, (Disk Access) • Orders queued by a shop • Hospital A&E • Printer Queue
Queues • Usually First in First Out(FIFO) • the first item (next to be used) • also called the head or the front • the last item (where we append additions to the queue) • also called the tail or the back
Queue • Once items are in the Queue they cannot be changed
Queue Operations • Create Queue • Delete Queue • enQueue • Serve • getHead • getTail • isFull
Create a Queue • We will need... • An array • Variables for the head + tail • An action to add something to the tail... • An action to serve from the head...
Errors • It should: • Throw an error if we try to add to a full queue • Throw an error if we try to remove from an empty queue
Queues Advanced: Cyclic Queue At the moment we have a limited space... Once the queue is used it is done... This can be sorted by looping back around...
Can we create this... • Need to have a quick algorithm that... • Notices the pointer is at the end of the list • Puts it to the start of the list • Does not over ride any data from the start of the list...
