171. Excel Sheet Column Number (Easy)

Given a column title as appear in an Excel sheet, return its corresponding column number.

For example:

    A -> 1B -> 2C -> 3...Z -> 26AA -> 27AB -> 28 

思路：
1.26进制转化为十进制，ord()函数；
2.逐个读入字符串中的每个字符进行处理转换；

class Solution():def titleToNumber(self, s):""":type s: str:rtype: int"""num = 0 for e in s:num = num * 26 + ord(e) - ord('A') + 1return num

 相关问题：http://www.cnblogs.com/yancea/p/7506456.html