LeetCode – Refresh – Exceel Sheet Column Title

Only trick is the 'Z'. Because when the number % 26 == 0, means there is a 'Z'. But when you n/=26, there is an extra 1 added to the n. EX:

27 % 26 = 1, 27 / 26 = 1  == > AA

26 % 26 = 0, 26 / 26 = 1  Here this extra one need to be removed. You can imagine that 'Z' becomes next around of the loop.

 

class Solution {
public:
    string convertToTitle(int n) {
        string result;
        while (n > 0) {
            int tmp = n%26;
            n /= 26;
            if (tmp == 0) {
                result = 'Z' + result;
                n--;
            } else {
                result = char(tmp + 'A' - 1) +result;
            }
        }
        return result;
    }
};