Lecture Notes on 22 Feb 2017

Read Chapter 2: Algorithm Analysis

class Stack (object):
  def __init__ (self):
    self.stack = []

  # add an item to the top of the stack
  def push (self, item):
    self.stack.append (item)

  # remove an item from the top of the stack
  def pop (self):
    return self.stack.pop()

  # check what an item is on the top of the stack
  def peek (self):
    return self.stack[-1]

  # check if stack is empty
  def isEmpty (self):
    return (len(self.stack) == 0)

  # return the number of elements in the stack
  def size (self):
    return (len(self.stack))