Hackerrank - Lucky number 8 - study code using dynamic programming

Hackerrank_luckyNumber8_studycode1.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Hackerrank_LuckyNumber8_DP_Studycode
{
    /*
     * Study dynamic programming solution 
     * 
     * questions on two things: 
     * first value is 1, count[0][0] = 1, why? 
     * second, count[n - 1][0] + Module - 1, why?
     */
    class Program
    {
        public static long Module = 1000000007;

        static void Main(string[] args)
        {
            int n = Convert.ToInt32(Console.ReadLine());

            String number = Console.ReadLine().ToString();

            int[][] count = new int[n][];  // subsequences 

            for (int i = 0; i < n; i++)
            {
                count[i] = new int[8];
            }

            int SIZE = 8; 
            count[0][0] = 0;  // ask why here?
            count[0][(number[0] - '0') % SIZE]++;

            // build a frequency table - 
            for (int i = 1; i < n; i++)
            {
                // subseqences - just ignore the current elment
                for (int remainder = 0; remainder < SIZE; remainder++)
                {
                    count[i][remainder] = count[i - 1][remainder];
                }
                
                // iterate each element in the array - go over all possible remainders in ascending order
                for (int remainder = 0; remainder < SIZE; remainder++)
                {
                    long current = count[i - 1][remainder];

                    // if the remainder's related count is 0, then no possible subsequences to the nextRemainder
                    // skip the remainder. 
                    if (current == 0)
                    {
                        continue; 
                    }

                    int nextRemainder = (10 * remainder + (number[i] - '0')) % SIZE;

                    count[i][nextRemainder] = (Int32)((count[i][nextRemainder] + current) % Module);
                }
            }

            Console.WriteLine((count[n - 1][0] + Module - 1) % Module);
            // Console.WriteLine((count[n - 1][0] + Module - 1) % Module);
        }
    }         
}