3.8.2 Stack

Knowledge Base > Algorithm > Data Structure

Overview

Stack is a very commonly used LIFO (Last-In-First-Out) data structure of which elements are placed in ordered such that elements can only be inserted or removed at one end, called top. In other words, since data is piled up in a stack, whenever an operation is being performed, element on the topmost comes off first. Therefore, in stack operations, we always handle the toppest element in stack at a time.

Basic Operation

• void push(<E>):
  Each push operation increases the size of the stack by 1, while the new data is being piled on top of the stack.
• <E> pop(void):
  Each pop operation decreases the size of the stack by 1, while the data on top of the stack is being ’popped’ out of the stack.
• <E> top(void):
  Similar to pop, top operation does return value of the top element of the stack, but top does not remove the element by reducing the size by one.

Source Code

Usually, a stack can be implemented by array or linked-list.

• Array Implemented Stack (C)
  
  
• Linked List Implemented Stack (C)

Related Topics

• Postfix Expression