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 n=s.length(); int res=0; for(int i=0;i<n;i++) { int tmp=s[i]-'A'+1; res=26*res+tmp; } return res; } };