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
很容易发现规律，例如AB = (‘A‘-‘A‘ + 1) * 26 + (B-‘A‘+1)
Java code:
public int titleToNumber(String s) { if(s == null) { return 0; } int sum = 0; for(int i = 0; i < s.length(); i++) { sum += (s.charAt(i) - ‘A‘ + 1) * Math.pow(26, s.length()-1-i); } return sum; }
Leetcode Excel Sheet Column Number
原文：http://www.cnblogs.com/anne-vista/p/4847648.html