8. String to Integer (atoi).py

class Solution:
    def myAtoi(self, s: str) -> int:
        s = s.strip()
        if not s:
            return 0

        i, num, sign = 0, 0, 1

        if s[0] == '+' or s[0] == '-':
            sign = -1 if s[0] == '-' else 1
            i += 1

        while i < len(s) and s[i].isdigit():
            digit = int(s[i])
            if num > (2**31 - 1 - digit) // 10:
                return 2**31 - 1 if sign == 1 else -2**31
            num = num * 10 + digit
            i += 1

        return sign * num