Given a column title as appear in an Excel sheet, return its corresponding column number.
本质上是一个进制转换问题。
1 class Solution { 2 public: 3 int titleToNumber(string s) { 4 int ret = 0; 5 for(int i = 0; i < s.size(); i ++) 6 ret = ret*26 + (s[i]-‘A‘+1); 7 return ret; 8 } 9 };
原文：http://www.cnblogs.com/desp/p/4334088.html