Excel Sheet Column Title

lc168

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 

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