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 

Solution

根据题意进行转化即可

Complexity

时间复杂度 O(n),空间复杂度 O(1)

Code

public class Solution {
    public String convertToTitle(int n) {
        StringBuffer sb = new StringBuffer();
        while (n > 0) {
            sb.insert(0,(char)((n - 1)%26 + 'A'));
            n  = (n - 1) / 26;
        }
        return sb.toString();
    }
}