题目链接：https://leetcode.com/problems/excel-sheet-column-number/
题目：
Related to question Excel Sheet Column Title
Given a column title as appear in an Excel sheet, return its corresponding column number.
For example:
A -> 1
B -> 2
C -> 3
...
Z -> 26
AA -> 27
AB -> 28
思路：
26进制转化为十进制
算法：
【Leetcode】Excel Sheet Column Number
原文：http://blog.csdn.net/yeqiuzs/article/details/51615481
