Excel Sheet Column Title

public class Solution {
    public String convertToTitle(int n) {
        StringBuffer sb = new StringBuffer();
        if(n <= 0)  return sb.toString();
        
        while(n != 0)
        {
            sb.append(getChar((n - 1)%26));
            n = (n - 1)/26;
        }
        return sb.reverse().toString();
    }
    public char getChar(int num)
    {
        return (char)(‘A‘ + num);
    }
}

public class Solution {
    public String convertToTitle(int n) {
        StringBuilder result = new StringBuilder();
        while(n>0)
        {
            result.append((char) ((n-1)%26 + (int)‘A‘));
            n = (n-1)/26;
        }
        return result.reverse().toString();
    }
}