leetcode Excel Sheet Column Title

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

For example:

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

关键在于n是先取模，再在赋值ASCII码的时候减去1，还是先减去1，再取模。纠结好久

class Solution {public:    string convertToTitle(int n) {        string re = "";                    while (n > 0) {            re += --n % 26 + 'A';             n /= 26;         }        reverse(re.begin(), re.end());                return re;    }};