private List <string> getTokens(string expression)
{
string operators = "()*/+-";
List <string> tokens = new List <string>();
StringMaker makeString = new StringMaker();
foreach (char c in expression.Replace(" ", string.Empty))
{
if (operators.IndexOf(c) >= 0)
{
if ((makeString.Length > 0))
{
tokens.Add(makeString.ToString());
makeString.Length = 0;
}
tokens.Add(c);
}
else
{
makeString.Append(c);
}
}
if ((makeString.Length > 0))
{
tokens.Add(makeString.ToString());
}
return(tokens);
}
private string getSubExpression(List <string> tokens, ref int i)
{
StringMaker subExpression = new StringMaker();
int banyakKurung = 1;
i += 1;
while (i < tokens.Count && banyakKurung > 0)
{
string token = tokens[index];
if (tokens[index] == "(")
{
banyakKurung += 1;
}
if (tokens[index] == ")")
{
banyakKurung -= 1;
}
if (banyakKurung > 0)
{
subExpression.Append(token);
}
i += 1;
}
if ((banyakKurung > 0))
{
throw new ArgumentException("Error Kurung");
}
return(subExpression.ToString());
}