How to implement stack in python?

Question

This is my attempt code in balanced input the last quiz for python intermediate.https://code.sololearn.com/c7qrPRYHlZHt/?ref=app but only the last test case is wrong.How to implement stack on that?

Answer 1

your code only check for opening and closing parenthesis count equals... so return true for unbalanced ')(' in example ;)

the stack needed here is so basic that you could implement it with a string or a list, or even a basic counter...

initialize counter to 0

iterate over chars:
when encountered '(' increment counter
when encountered ')' check if counter == 0 then return false, else decrement counter

at end of iterations, return true if counter == 0 else return false