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
class Solution { public: int titleToNumber(string s) { int colNum = 0; for(int i = 0; i < s.length(); i++) colNum = colNum * 26 + (s[i] - '@'); return colNum; } };