Leetcode 232. Implement Queue using Stacks - Python

Implement a first in first out (FIFO) queue using only two stacks. The implemented queue should support all the functions of a normal queue (push, peek, pop, and empty).
Implement the MyQueue class:
void push(int x) Pushes element x to the back of the queue.
int pop() Removes the element from the front of the queue and returns it.
int peek() Returns the element at the front of the queue.
boolean empty() Returns true if the queue is empty, false otherwise.
Notes:
You must use only standard operations of a stack, which means only push to top, peek/pop from top, size, and is empty operations are valid.
Depending on your language, the stack may not be supported natively. You may simulate a stack using a list or deque (double-ended queue) as long as you use only a stack's standard operations.

[@ИльяСмирнов-ж8я]

This feeling then you are a completely noob in Python, went to KZbin because you code didn't work... and see this video and think about pop(0) instead of the second stack.

[@khalilsleimi7832]

An alternative solution might be to have one stack hold input values, and the other stack holds the output values. You just add to the input stack when pushing. And when you need to peek or pop, you just check if the output stack is nonempty and return the poped/peeked value from that stack, otherwise, you flip the values from the input to the output and then pop/peek. Of course, it'll depend on where you want most of the computing to be spent, when writing data or when reading data

[@jaskibrother]

This is a great solution and explanation!!

[@santhakumar20]

such a awesome explanation ...

[@Guy9221]

Time complexity analysis?

[@nandinirm2234]

Good explanation Font size should have been mobile user friendly

[@nagendrabommireddi8437]

thank you

[@mitramir5182]

Thank you so much, I was really lost since I've just started learning about data structures! but your explanation was amazing!

[@tomleeyrc40]

This reminds me of the towers of hanoi solution, thank you for this explanation

[@pythonicd1239]

I got memory limit exceeded for the same code but thanks for the video

[@kiitanayandosu-ug7pe]

Amazing explanation

[@maged_helmy]

Glad it was helpful!

[@nikitasinha8181]

Thank you so much

[@maged_helmy]

You're most welcome

[@lucynowacki3327]

.push() is O(n) , .pop() is O(1)

[@sriharsha2027]

Thanks a lot bro your explanation is very good