2390. Removing Stars From a String

[fockspaces]

1. 用 stack 概念
2. 遇到星星則刪最後一個
3. 否則，append char

class Solution:
    def removeStars(self, s: str) -> str:
        ans = ""
        for c in s:
            if c == '*':
                ans = ans[:-1]
            else:
                ans += c
        return ans

[fockspaces]

GPT improve: 用 stack 實作，string concatenation 效率不好

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