$[12$:$45$ AM$,10/21/2024]$ Sneha Giranje: What is the missing piece of code found in the push function?

Given two queues, implement a last$-$in$-$first$-$out $($LIFO$)$ stack. The implemented stack supports all the functions of a normal stack $($push$,$ top, pop, and empty$).$

The MyStack class consists of the following functions:

$*$ void push$($int x$)$ Pushes element x to the top of the stack.

$*$ int pop $()$ Removes the element on the top of the stack and returns it$.$

$*$ int top $()$ Returns the element on the top of the stack.

$*$ boolean empty $()$ Returns true if the stack is empty, false otherwise.

Notes:

$*$ You must use only standard operations of a queue, which means that only push to back, peek$/$pop from front, size and is empty operations are valid.

$*$ Depending on your language, the queue may not be supported natively. You may simulate a queue using a list or deque $($double$-$ended queue$)$ as long as you use only a queue's standard operations.

Example $1$:

Input

$["$MyStack$",$ "push", "push",

"top", "pop",

"empty"$]$

$[0],[1],[2],[],[],033$

output

$[$nu$11,$ nu$11,$ null, $2,2,$

false$]$

Explanation

MyStack myStack $=$ new MyStack$()$;

myStack. push $(1)$ ; myStack, push $(2)$ ;

myStack, top $()$; $//$ return $2$ myStack, pop$)$; $//$ return $2$ myStack, empty$)$; $//$ return False

$[12$:$47$ AM$,10/21/2024]$ Sneha Giranje: What is the missing piece of code found in the push function?

class MyStack:

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

self.q $=$ deque $()$

self.t $=$ None

def push $($self$,$ x: int$)->$ None:

if self.t:

$1/$ add missing line of code here

self.t $=$ x

def pop $($self$)->$ int:

result $=$ self.t

newg $=$ degue $()$

while len $($self$.$q$)1$:

newg append $($self$.$q$.$ popleft$()$

self.t $=$ self.q$-$popleft$()$ if self.q else None

self.q $=$ newg

return result

def top$($self$)$ int:

return self.t

def empty $($self$)$ bool: return self.t is None

self.q $=$ deque$)$

self.q$.$append$($self$.$q$.$popleft$)$

self.q$.$append$($self$.$t$)$

return self.$|[-1]$

none of the above