Leetcode-8

Question

Solution

首先用strip去掉str前面的空格，然后判断是否为空。之后根据第一个元素判断正负。然后就是读取数据了。

class Solution:
    def myAtoi(self, str: str) -> int:
        ls = str.strip()
        if len(ls) == 0:
            return 0
        if ls[0] == '-':
            sign = -1
        else:
            sign = 1
        if ls[0] in ['+', '-']:
            ls = ls[1:]
        num, i = 0, 0
        while i < len(ls) and ls[i].isdigit():
            num = num * 10 + int(ls[i])
            i += 1
        return max(-2**31, min(sign * num, 2**31-1))