I. Write the code to implement a stack USING C$++$

You may use the programming language of your choice

You may refer to the below is the implementation code in python

class Stack:

def $\_\_$init$\_\_($self$)$:

self.items $=[]$

self.top $=-1$

def is$\_$empty$($self$)$:

return self.top $==-1$

Your code should contain the following $(9$ marks :$3$ marks each$)$

$1.$ Pop$($self$)$

$2.$ push$($self$,$ item$)$

$3.$ size$($self$)$

$4.$ Write the code to evaluate a post fixed expression using a stack method you have defined above.$(10$ marks$)$