Excel Column Num to Alpha-26

excel_column_name.cs

using System.Text;

public class Hello{
    public static void Main(){
        // Your code here!
        
        System.Console.WriteLine("Hello C#");
        System.Console.WriteLine($"??? => {DIC_ALPHABET[0]}");
        
        for (int i = 1; i <= 16384; i++)
            System.Console.WriteLine($"{i} => {numToAlphabet(i)}");
    }
    
    private const string DIC_ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    public static string numToAlphabet(int num) {
        
        var sb = new StringBuilder();
        while (num > 0) {
            var mod = (num - 1) % DIC_ALPHABET.Length;
            sb.Insert(0, DIC_ALPHABET[mod]);
            num = (num - mod) / DIC_ALPHABET.Length;
        }
        
        return sb.ToString();
    }
}