Excel Sheet Column Title(Easy)

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

Java代码

public String convertToTitle(int n) {
    String res = "";
    while(n != 0) {
        char ch = (char)((n - 1) % 26 + 'A');
        n = (n - 1) / 26;
        res = ch + res;
    }
    return res;
}