题目描述：
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
解题思路：
26进制。
代码如下：
public class Solution {
public String convertToTitle(int n) {
StringBuilder sb = new StringBuilder();
while(n > 0){
n--;
sb.insert(0, (char)(‘A‘ + (n % 26)));
n /= 26;
}
return sb.toString();
}
}
Java [Leetcode 168]Excel Sheet Column Title
原文：http://www.cnblogs.com/zihaowang/p/5206529.html