Problem URL: Removing stars from a string

We will use a stack to store the characters of the string. If the current character is a star, we will pop the last character from the stack. If the current character is not a star, we will push it to the stack. At the end, we will return the stack as a string.

class Solution:
    def removeStars(self, s: str) -> str:
        stack = []
        for ch in s:
            if ch == '*':
                stack.pop()
            else:
                stack.append(ch)
        return ''.join(stack)

Time complexity: O(n)
Space complexity: O(n)