Consider that a Stack class has been implemented containing the push$($element$),$ pop$(),$ peek$()$ and isEmpty$()$ functions.

Complete the function conditional$\_$reverse$()$ which will take an object of Stack class as an input that contains some integer values. The function returns a new stack which will contain the values in reverse order from the given stack except the consecutive one$$s$.$ You cannot use any other data structure except Stack.

Note: The Stack class implements a singly linked list$-$based Stack hence overflow is not possible. The pop$()$ and peek$()$ functions return None in case of the underflow.

In the following example, consider the rightmost element to be the topmost element of the stack.

Sample Input Stack

$($Rightmost is the top$)$

Output Reversed Stack $($Rightmost is the top$)$

Explanation

Stack: $10,10,20,20,30,10,50$

Top $=50$

New Stack: $50,10,30,20,10$

Top $=10$

Consecutive $20$ and $10$ are not present in the output reversed stack

Driver code:

def conditional$\_$reverse$($stack$)$:

#To Do

print$(\text{'}$Test $01\text{'})$

st$=$Stack$()$

st$.$push$(10)$

st$.$push$(10)$

st$.$push$(20)$

st$.$push$(20)$

st$.$push$(30)$

st$.$push$(10)$

st$.$push$(50)$

print$(\text{'}$Stack:$\text{'})$

print$\_$stack$($st$)$

print$(\text{'}------\text{'})$

reversed$\_$stack$=$conditional$\_$reverse$($st$)$

print$(\text{'}$Conditional Reversed Stack:$\text{'})$

print$\_$stack$($reversed$\_$stack$)$ # This stack contains $50,10,30,20,10$ in this order whereas top element should be $10$

print$(\text{'}------\text{'})$

Linked List based Stack is implemented in the following cell.

class Node:

def $\_\_$init$\_\_($self$,$elem$=$None,next$=$None$)$:

self.elem $=$ elem

self.next $=$ next

class Stack:

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

self.$\_\_$top $=$ None

def push$($self$,$elem$)$:

nn $=$ Node$($elem$,$self.$\_\_$top$)$

self.$\_\_$top $=$ nn

def pop$($self$)$:

if self.$\_\_$top $==$ None:

#print$(\text{'}$Stack Underflow'$)$

return None

e $=$ self.$\_\_$top

self.$\_\_$top $=$ self.$\_\_$top.next

e$.$next $=$ None

return e$.$elem

def peek$($self$)$:

if self.$\_\_$top $==$ None:

#print$(\text{'}$Stack Underflow'$)$

return None

return self.$\_\_$top.elem

def isEmpty$($self$)$:

return self.$\_\_$top $==$ None

#You can run this driver code cell to understand the methods of Stack class

st $=$ Stack$()$

st$.$push$(4)$

st$.$push$(3)$

st$.$push$(5)$

st$.$push$(1)$

st$.$push$(9)$

print$(\text{'}$Peeked Element: $\text{'},$st$.$peek$())$

print$(\text{'}$Popped Element: $\text{'},$st$.$pop$())$

print$(\text{'}$Popped Element: $\text{'},$st$.$pop$())$

print$(\text{'}$Popped Element: $\text{'},$st$.$pop$())$

print$(\text{'}$Peeked Element: $\text{'},$st$.$peek$())$

print$(\text{'}$Popped Element: $\text{'},$st$.$pop$())$

print$(\text{'}$Popped Element: $\text{'},$st$.$pop$())$

print$(\text{'}$Peeked Element: $\text{'},$st$.$peek$())$

print$(\text{'}$Popped Element: $\text{'},$st$.$pop$())$

print$($st$.$isEmpty$())$

You can print your stack using this code segment

def print$\_$stack$($st$)$:

if st$.$isEmpty$()$:

return

p $=$ st$.$pop$()$

print$(\text{'}|\text{'},$p$,$end$=\text{'}\text{'})$

if p$<10$:

print$(\text{'}|\text{'})$

else:

print$(\text{'}|\text{'})$

#print$(\text{'}------\text{'})$

print$\_$stack$($st$)$

st$.$push$($p$)$

# st $=$ Stack$()$

# st$.$push$(4)$

# st$.$push$(3)$

# st$.$push$(5)$

# st$.$push$(1)$

# st$.$push$(9)$

# print$\_$stack$($st$)$

# print$(\text{'}------\text{'})$