contapagine

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

namespace ContaPagine
{
    class Program
    {
        static void Main(string[] args)
        {
            int NUM_MIN = 1, NUM_MAX = 708, STUD = 26;
            int[] contatore = new int[NUM_MAX - NUM_MIN];
            for (int i = NUM_MIN; i <= NUM_MAX; i++)
            {
                if (i <= STUD)
                    contatore[i - NUM_MIN]++;
                else
                {
                    int val = SommaCifre(i);
                    while (val > STUD) val = SommaCifre(val);
                    contatore[val - 1]++;
                }
            }
            for(int i = NUM_MIN; i < NUM_MAX; i++)
            {
                if (contatore[i - NUM_MIN] != 0)
                {
                    Console.WriteLine("{0} :\t{1:0.000}", i - NUM_MIN + 1, (double)contatore[i - NUM_MIN] * 100 / (NUM_MAX - NUM_MIN));
                }
            }
            Console.ReadKey();
        }
        static int SommaCifre(int n)
        {
            int s = 0;
            foreach (char c in n.ToString().ToCharArray()) s += Convert.ToInt16(c.ToString());
            return s;
        }
    }
}