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

/*
 *Algoritm de transformare a unui şir de caractere în număr real.
 */

namespace P26
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Introduceti un numar care va fi salvat sub forma de STRING si va fi convertit in DOUBLE !");
            Console.WriteLine();

            Console.Write("string : ");
            string numString = Console.ReadLine();
            Console.WriteLine();

            string noContain = " qwertyuiopasdfghjklzxcvbnm !@#$%^&*()_+[]{}|:;'<>?,/'= ";

            int j = howMany(numString, '.');

            while ((isContained(numString, noContain)) || (howMany(numString , '.') > 1))
            {
                Console.WriteLine("Invalid !!! Reintroduceti : ");
                Console.WriteLine();
                Console.Write("string : ");
                numString = Console.ReadLine();
                Console.WriteLine();
            }


            double num = convertToDouble(numString);

            Console.WriteLine("DOUBLE-ul este : " + num);
            Console.WriteLine();


        }

        private static double convertToDouble(string numString)
        {
            double total = 0, totalINT = 0, totalFRA = 0;

            int start = 0;

            if(isContained(numString, "-"))
            {
                start = 1;
            }

            if(isContained(numString, "."))
            {
                string[] parts = numString.Split('.');

                for (int i = start; i < parts[0].Length; i++)
                {
                    totalINT = totalINT * 10 + (parts[0][i] - '0');
                }

                for (int i = 0; i < parts[1].Length; i++)
                {
                    totalFRA = totalFRA * 10 + (parts[1][i] - '0');
                }

                totalFRA = totalFRA / Math.Pow(10, parts[1].Length);

                total = totalINT + totalFRA;

                return total * ((start == 1) ? -1 : 1);
            }
            else
            {
                for(int i = start; i < numString.Length; i++)
                {
                    total = total * 10 + (numString[i] - '0');
                }

                return total * ((start == 1) ? -1 : 1);

            }
        }

        private static int howMany(string numString, char s)
        {
            int i = 0;

            foreach(char c in numString)
            {
                if(c == s)
                {
                    i++;
                }
            }

            return i;
        }

        private static bool isContained(string numString, string noContain)
        {
            foreach (char c in noContain)
            {
                if (numString.Contains(c))
                {
                    return true;
                }
            }

            return false;

        }

    }
}