168. Excel Sheet Column Title - cocoder39/coco39_LC GitHub Wiki

168. Excel Sheet Column Title

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

27 = 1*26 + 1 = A*26 + A => how to make 1 = A

n%26 + A - 1 or n--; n%26 + A? => test with 26 = Z

string convertToTitle(int n) {
        string res;
        while (n > 0) {
            n--;
            res.push_back(n % 26 + 'A'); 
            n /= 26;
        }
        reverse(res.begin(), res.end());
        return res;
    }