Challenge: Implement Two Stacks Using One List

Problem Statement

Implement the following functions to implement two stacks using a single array such that for storing elements both stacks should use the same array. An illustration is also provided for your understanding. Also, for this problem, initialize a Python list with the provided fixed size and perform all the operations in-place without growing or shrinking the list!

Function Prototypes

def push1(value): # pushes value in stack 1
def push2(value): # pushes value in stack 2
def pop1(): # pops an element from stack 1 
def pop2():# pops an element from stack 2 

Input/Output

push1(value)

Input: an integer

Output: inserts the given value in the first stack, i.e., stack1

push2(value)

Input: an integer

Output: inserts the given value in the second stack i.e stack2

pop1()

Output: returns and removes the top value of stack1

pop2()

Output: returns and removes the top value of stack2