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
思路简单，这里没有使用pow求n次方，而是使用变量t来保存
int titleToNumber(string s) { int sum = s[s.length() - 1] - ‘A‘ + 1; int t = 26; for (int i = s.length() - 2; i >= 0; --i, t *= 26) sum += (s[i] - ‘A‘ + 1) * t; return sum; }
Excel Sheet Column Number leetcode
原文：http://www.cnblogs.com/sdlwlxf/p/5140384.html