Chapter Seven
Stacks

• Click here to see an example of push and pop in a stack

 
• The behavior of a stack
• a list of items that are accessible at only one end of the list.
• items are added (PUSH) or deletd (POP) from the list only at the top of the stack.
• last in first out (LIFO)
• The STL stack container is an adapter class, because it uses either

a vector, deque, or list to implement the behavior of a stack.
• Since we do not use a stack to insert or delete any item at any position other than top,

there is little benifit using a list to store the stack's elements.
• The deque manages memory more efficiently than a vector.
• Write your own stack class and click here to see the description.
• class miniStack
• Use a vector object maintains the stack items and size.
• Be able to push an item to the top, pop the item from the top,

reference the top element, check it empty or not and maintain the size of the stack.
•   miniStack();  // constructor. create an empty stack
•   void push(const T& item);
•   void pop();
•   T& top();
•   const T& top() const;
•   bool empty() const;
•   int size() const;
• Call vector's operators to define stack's operators. (back <---> top)

For example,
template <typename T>
void miniStack<T>::push(const T& item)
{
 stackVector.push_back(item);
}
• Click here to see the code of class miniStack.
• Infix and Postfix Notations for Expression Evaluation
• Example of evaluating a postfix expression
• Example of converting infix to postfix
• Example of stack
   
• Applications for stacks in a computer program:
• reverses a word
• balancing brackets
• multiBase     Code for converting decimal number to binary
• expression evaluation
• implementing recursive function calls
• uncoupling stack elements:
• See Figure 7-5 on page 336
• See program 7.2