An Introduction to Data Structures

Chapter 16: An Introduction to Data Structures II

To learn about stacks and queues
To become familiar with common containers and algorithms from the Standard Template Library

Stacks and queues are special data types that allow insertion and remove of items at the ends only, not in the middle.
A stack lets you insert and remove elements at one end only, traditionally called the top of the stack.
To visualize a stack, think of a stack of books.
Since items can only be added or removed from the top of the stack, they are removed in the order that is opposite from the order they were added.
This is called last in, first out or LIFO order.
The addition and removal operations are called push and pop.

The is a stack template in the standard C++ library.

stack<string> s;
s.push("Tom");
s.push("Dick");
s.push("Harry");
while (s.size() > 0)
{  cout << s.top() << "\n";
   s.pop();
}

A queue is similar to a stack, except that you add items to one end of the queue (the back) and remove them from the other end of the queue (the front).
To visualize a queue, think of people lining up.
Queues store items in a first in, first out or FIFO fashion.

The standard queue template implements a queue in C++.

queue<string> q;
q.push("Tom");
q.push("Dick");
q.push("Harry");
while (q.size() > 0)
{  cout << q.front() << "\n";
   q.pop();
}

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