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进制转换
代码1：
class Solution { public: int titleToNumber(string s) { int res=0; for(char ch:s){ char temp = ch-'A'+1; res = res*26 + temp; } return res; } };代码2：
class Solution { public: int titleToNumber(string s) { int res=0; for(char ch:s){ char temp = ch-'A'+1; res = res*26 + temp; } return res; } };代码3：
class Solution { public: int titleToNumber(string s) { int res = 0; for (char c:s) { res *= 26; res += c - 'A' + 1; } return res; } };