[leetCode]168. Excel Sheet Column Title

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

For example:

1 -> A2 -> B3 -> C...26 -> Z27 -> AA28 -> AB 

解题思路
这题类比26进制，不同之处在于1-26而非0-25，所以每次求余之前先减一。
java代码

public String convertToTitle(int n) {        StringBuilder s = new StringBuilder();        while (n > 0){            s = s.append((char)(((n - 1) % 26) + 'A'));            n = (n - 1) / 26;        }        return s.reverse().toString();    }