Excel Sheet Column Number

    A -> 1
    B -> 2
    C -> 3
    ...
    Z -> 26
    AA -> 27
    AB -> 28 

class Solution {
public:
    int titleToNumber(string s) {
        int sum = 0,temp=0;
        for(int i=0;i<s.size();i++)
        {
            sum=temp+(s[i]-'A'+1);
            temp = sum*26;
        }
        return sum;
    }
};