171.py

from functools import reduce
class Solution:

    # 按照26进制数处理
    def titleToNumber(self, s):
        dict = {"A": 1, "B": 2, "C": 3, "D": 4, "E": 5, "F": 6, "G": 7, "H": 8, "I": 9, "J": 10, "K": 11,
                "L": 12, "M": 13, "N": 14, "O": 15, "P": 16, "Q": 17, "R": 18, "S": 19, "T": 20, "U": 21,
                "V": 22, "W": 23, "X": 24, "Y": 25, "Z": 26}
        num = 0
        for i in range(len(s)):
            num = num + dict[s[i]] * pow(26, (len(s) - i - 1))
        return num

    def titleToNumber1(self, s):
        s_len = len(s) - 1
        res = 0
        for idx, char in enumerate(s):
            res += (ord(char) - 64) * 26 ** (s_len - idx)
        return res

    # Using reduce
    def titleToNumber2(self, s):
        return reduce(lambda x, y: x*26+y, map(lambda x: ord(x) - ord('A')+1, s))

if __name__ == "__main__":
    print(Solution().titleToNumber2("ZY"))