leetcode每日一题65.有效数字

class Automaton:
def __init__(self):
self.state = ‘start‘
self.isNum = False
self.table = {
‘start‘: [‘start‘,‘signed‘,‘integer‘,‘sDot‘, ‘end‘,‘end‘],
‘signed‘: [‘end‘,‘end‘,‘integer‘,‘sDot‘,‘end‘, ‘end‘],
‘integer‘: [‘eSpace‘,‘end‘,‘integer‘,‘dot‘,‘e‘,‘end‘],
‘sDot‘:[‘end‘,‘end‘,‘decimals‘,‘end‘,‘end‘,‘end‘],
‘dot‘: [‘eSpace‘,‘end‘,‘decimals‘,‘end‘,‘e‘,‘end‘],
‘decimals‘: [‘eSpace‘,‘end‘,‘decimals‘,‘end‘,‘e‘,‘end‘],
‘e‘: [‘end‘,‘eSigned‘,‘index‘,‘end‘,‘end‘,‘end‘],
‘eSigned‘: [‘end‘,‘end‘,‘index‘,‘end‘,‘end‘,‘end‘],
‘index‘: [‘eSpace‘,‘end‘,‘index‘,‘end‘,‘end‘,‘end‘],
‘eSpace‘: [‘eSpace‘,‘end‘,‘end‘,‘end‘,‘end‘,‘end‘]
}
def get_col(self, c):
if c.isspace():
return 0
if c == ‘+‘ or c == ‘-‘:
return 1
if c.isdigit():
return 2
if c == ‘.‘:
return 3
if c == ‘e‘:
return 4
return 5
def get(self, c):
self.state = self.table[self.state][self.get_col(c)]
if self.state == ‘start‘:
self.isNum = False
elif self.state == ‘signed‘:
self.isNum = False
elif self.state == ‘integer‘:
self.isNum = True
elif self.state == ‘sDot‘:
self.isNum = False
elif self.state == ‘dot‘:
self.isNum = True
elif self.state == ‘decimals‘:
self.isNum = True
elif self.state == ‘e‘:
self.isNum = False
elif self.state == ‘eSigned‘:
self.isNum = False
elif self.state == ‘index‘:
self.isNum = True
elif self.state == ‘end‘:
self.isNum = False
elif self.state == ‘eSpace‘:
self.isNum = True
class Solution:
def isNumber(self, s: str) -> bool:
automaton = Automaton()
for c in s:
automaton.get(c)
if automaton.state == "end":
break
return automaton.isNum