🟡 剑指 Offer 20. 表示数值的字符串

LeetCode 提示

题目难度 中等

原题链接 🔗 leetcode

题解 1.py

# from enum import Enum
# class Status(Enum):#     Start = 1#     Symbol1 = 2#     NoIntFloat = 3#     Int1 = 4#     Float1 = 5#     LetterE = 6#     Symbol2 = 7#     Int2 = 8#     Ending = 9
statusMap = {    1: {        'd': 3,        's': 1,        'b': 2,        'n': 4,    },    2: {        'n': 4,        'd': 3,    },    3: {        'n': 5,    },    4: {        's': 9,        'e': 6,        'd': 5,        'n': 4,    },    5: {        'n': 5,        's': 9,        'e': 6,    },    6: {        'b': 7,        'n': 8,    },    7: {        'n': 8,    },    8: {        'n': 8,        's': 9,    },    9: {        's': 9,    },}
class Solution:    def isNumber(self, s: str) -> bool:        def parse(ch):            if ch == ' ':                return 's'            if ch == '+' or ch == '-':                return 'b'            if ch <= '9' and ch >= '0':                return 'n'            if ch == 'e' or ch == 'E':                return 'e'            if ch == '.':                return 'd'            return 'x'        cur = 1        for c in list(s):            p = parse(c)            if p not in statusMap[cur]:                return False            cur = statusMap[cur][p]        return 's' in statusMap[cur] and statusMap[cur]['s'] == 9