'''
A valid number can be split up into these components (in order):

    A decimal number or an integer.
    (Optional) An 'e' or 'E', followed by an integer.

A decimal number can be split up into these components (in order):

    (Optional) A sign character (either '+' or '-').
    One of the following formats:
        At least one digit, followed by a dot '.'.
        At least one digit, followed by a dot '.', followed by at least one digit.
        A dot '.', followed by at least one digit.

An integer can be split up into these components (in order):

    (Optional) A sign character (either '+' or '-').
    At least one digit.

For example, all the following are valid numbers: ["2", "0089", "-0.1", "+3.14", "4.", "-.9", "2e10", "-90E3", "3e+7", "+6e-1", "53.5e93", "-123.456e789"], while the following are not valid numbers: ["abc", "1a", "1e", "e3", "99e2.5", "--6", "-+3", "95a54e53"].

Given a string s, return true if s is a valid number.
'''

class Solution:
    def isNumber(self, s: str) -> bool:
        num, dec, exp, sign = False, False, False, False
        for i in s:
            print(num, dec, exp, sign)
            if i == 'e' or i == 'E':
                if exp or not num:
                    return False
                num, dec, exp, sign = False, False, True, False
            elif i>='0' and i<='9':
                num = True
            elif i == '.':
                if dec or exp:
                    return False
                dec = True
            elif i == '+' or i == '-':
                if sign or num or dec:
                    return False
                else:
                    sign = True
            else:
                return False

        return num


# for n in ["2", "0089", "-0.1", "+3.14", "4.", "-.9", "2e10", "-90E3", "3e+7", "+6e-1", "53.5e93", "-123.456e789", '-']:
# for n in ["abc", "1a", "1e", "e3", "99e2.5", "--6", "-+3", "95a54e53"]:
print(Solution().isNumber("-1."))
