168. Excel Sheet Column Title

题目：

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 

链接： http://leetcode.com/problems/excel-sheet-column-title/

2/20/2017, Java

看别人的解法，从最低位开始算

一开始想从最高位开始算，然而高位是在之前低位运算基础上来的。

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