LeetCode题解(1797)：设计一个验证系统(Python)

题目：​​原题链接​​（中等）

标签：设计、哈希表、堆

解法	时间复杂度	空间复杂度	执行用时
Ans 1 (Python)	$O(NlogN)$	$O(N)$	112ms (97.87%)
Ans 2 (Python)
Ans 3 (Python)

解法一：

class AuthenticationManager:

    def __init__(self, timeToLive: int):
        self.ttl = timeToLive
        self.timeline = []
        self.tokens = {}

    def generate(self, token: str, current: int) -> None:
        self._remove(current)
        if token not in self.tokens:  # 题目保证独一无二
            self.tokens[token] = current + self.ttl
            heapq.heappush(self.timeline, (current + self.ttl, token))

    def renew(self, token: str, current: int) -> None:
        self._remove(current)
        if token in self.tokens:
            self.tokens[token] = current + self.ttl
            heapq.heappush(self.timeline, (current + self.ttl, token))

    def countUnexpiredTokens(self, current: int) -> int:
        self._remove(current)
        return len(self.tokens)

    def _remove(self, current):
        """移除过期验证码"""
        while self.timeline and self.timeline[0][0] <= current:
            time, token = heapq.heappop(self.timeline)
            if token in self.tokens and self.tokens[token] == time:
                self.tokens.pop(token)