using System;

using System.Data;

using System.Collections.Generic;

​

namespace roundQualtrics

{

  public class Pointer

  { 

    public int Position { get; set; }

    public int Difference { get; set; }

  }

​

  public class Fragment

  {

    public int Nivel { get; set; }

    public int Position { get; set; }

    public int Length { get; set; }

    public string Value { get; set; }

  }

    public class Program

    {

        public static void Main(string[] args)

        {

            string round = "round((round((20 * (100-0 -0 - 0))/ 100, 2) + round((50  * (100-0-0-0))/100,2) + round ((30 * (100-0-0-0)) /100,2) + round((0*(100- - -))/100,2) + round((0 * (100 - - -) )/100,2)) / ((100-0) /100),2) % ";

            //round = "round((20 * (100-0 -0 - 0))/ 100, 2) + round ((30 * (100-0-0-0)) /100,2) % ";

​

            string result = strEvaluate(round);

            Console.WriteLine(result);

​

        }

        public static string strEvaluate(string strQualtrics)

        {

          int diff = 0;

          int textSize = 0;

          string subtext = "";

          string result = "";

          DataTable dt = new DataTable();

          Stack<Pointer> reader = new Stack<Pointer>();

          Stack<Fragment> lstPartial = new Stack<Fragment>();

​

          string strCalculo = "round(("+strQualtrics + "),2)";

          strCalculo = strCalculo.Replace(" ", "");

          while (strCalculo.IndexOf("--") >= 0)

              strCalculo = strCalculo.Replace("--", "-");

          while (strCalculo.IndexOf("++") >= 0)

              strCalculo = strCalculo.Replace("++", "+");

          strCalculo = strCalculo.Replace("-)", ")");

          strCalculo = strCalculo.Replace("+)", ")");

​

          try

          {

              for (int i = 0; i < strCalculo.Length; i++)

              { 

                  string s = strCalculo.Substring(i, 1);

                  if (s.Equals("r"))

                  {

                      i += 5;

                      if (reader.Count == 0)

                          diff = 0;

                      else

                          diff = reader.Peek().Difference;

                      reader.Push(new Pointer() { Position = i + 1, Difference = diff });

                  }

                  else if (s.Equals(","))

                  {

                      Pointer ptReader = reader.Pop();

                      subtext = strCalculo.Substring(ptReader.Position, i - ptReader.Position);

                      textSize = subtext.Length;

​

                      if (lstPartial.Count > 0)

                      { 

                          while (lstPartial.Peek().Nivel > reader.Count)

                          {

                              Fragment ptFragment = lstPartial.Pop();

                              subtext = subtext.Substring(0, ptFragment.Position-6) + ptFragment.Value +subtext.Substring(ptFragment.Position+3+ptFragment.Length);

                              if (lstPartial.Count == 0)

                                  break;

                          }

                      }

​

                     subtext = Math.Round(Convert.ToDouble(dt.Compute(subtext, "")), 2).ToString();

                     lstPartial.Push(new Fragment() { Nivel = reader.Count, Position = ptReader.Position - 6, Length = textSize, Value = subtext });        

                  }               

              }

              if (lstPartial.Count > 0)

                  result = lstPartial.Pop().Value;

​

              if (strQualtrics.Substring(strCalculo.Length-1).Equals("%"))

                  result +="%";

​

              return result;

          }

          catch

          {

               return "";   

          }

        }

​

    }

}