CSS446Spring 2014

Nan Wang

Java Collection Framework◦ Stack◦ Queue & Priority Queue

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A hierarchy of interface types and classes for collecting objects. Each interface type is implemented by one or more classes.

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A stack remembers the order of its elements, but it does not allow you to insert elements in every position.

You can add and remove elements only at the top.

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A stack is a collection of elements with last-in, first-out retrieval (LIFO).

Undo feature in word processor Run-time stack that a processor or virtual

machine keeps to store the values of variable in nested methods.

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In a queue, you add items to one end (the tail) and remove them from the other end (the head).

A priority queue is an unordered collection that has an efficient operation for removing the element with the highest priority. (reading assignments)

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Bus Stop

frontrear

rear rear rear rear

A Queue is a collection of elements with first-in first-out retrieval.

Print queue

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A priority queue collects elements, each of which has a priority.

Elements are retrieved according to their priority.

New elements can be inserted in any order. Removing an element from a priority queue,

the element with the most urgent priority is retrieved.

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Because the priority queue needs to be able to tell which element is the smallest, the added elements should belong to a class that implements the Comparable interface!!!

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Java How to Program 9th

Chapter 7 ,8,9,10, 11,18,20 review questions

Big Java Chapter 7-13,15 Review Questions

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