Excel Sheet Column Number

Excel Sheet Column Number

 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 

---------------------------------- thinking -----------------------------------------

Too simple. Just learn how to use iterator!!

---------------------------------- codes --------------------------------------------

class Solution {
public:
    int titleToNumber(string s) {
        int result = 0;
        std::string::iterator it;
        for (it = s.begin(); it != s.end(); ++it) {
            char cur = *it;
            result = 26 * result + cur - 'A' + 1;
        }
        return result;
    }
};