题目：

题解：

INT_MAX = 2 ** 31 - 1
INT_MIN = -2 ** 31class Automaton:def __init__(self):self.state = 'start'self.sign = 1self.ans = 0self.table = {'start': ['start', 'signed', 'in_number', 'end'],'signed': ['end', 'end', 'in_number', 'end'],'in_number': ['end', 'end', 'in_number', 'end'],'end': ['end', 'end', 'end', 'end'],}def get_col(self, c):if c.isspace():return 0if c == '+' or c == '-':return 1if c.isdigit():return 2return 3def get(self, c):self.state = self.table[self.state][self.get_col(c)]if self.state == 'in_number':self.ans = self.ans * 10 + int(c)self.ans = min(self.ans, INT_MAX) if self.sign == 1 else min(self.ans, -INT_MIN)elif self.state == 'signed':self.sign = 1 if c == '+' else -1class Solution:def myAtoi(self, str: str) -> int:automaton = Automaton()for c in str:automaton.get(c)return automaton.sign * automaton.ans