Problem

Given a column title as appear in an Excel sheet, return its corresponding column number.

Example

For example:

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

Input: "A"
Output: 1

Input: "AB"
Output: 28

Input: "ZY"
Output: 701

Code

static int var = [](){
    std::ios::sync_with_stdio(false);
    cin.tie(NULL);
    return 0;
}();
class Solution {
public:
    int titleToNumber(string s) {
        int res = 0;
        for(int i=0;i<s.size();i++){
            res = res*26 + (s[i]-64);
        }
        return res;
    }
};

Result

171. Excel Sheet Column Number.png