static void Main(string[] args)
{
void Menu()
{
StringBuilder menu = new StringBuilder();
menu.AppendLine("Select an option: ");
menu.AppendLine("\t a.Enter in variables(must be done before evaluating)");
menu.AppendLine("\t b.Enter equation ");
menu.AppendLine("\t c.Evaluate");
menu.AppendLine("\t d.Clear Equation");
menu.AppendLine("\t e.Clear Variables");
menu.AppendLine("\t q.Quit");
Console.WriteLine(menu);
}
Dictionary <string, double> variables = new Dictionary <string, double>();
string equation = string.Empty;
char selection = '0';
while (selection != 'q')
{
if (equation != string.Empty)
{
Console.WriteLine("Current equation = " + equation);
}
Menu();
selection = char.Parse(Console.ReadLine());
selection = char.ToLower(selection);
switch (selection)
{
case ('a'):
string varname = string.Empty;
int value;
Console.Clear();
Console.WriteLine("Enter in the variable name: ");
varname = Console.ReadLine();
varname = varname.Replace(" ", string.Empty);
Console.WriteLine("Enter in the variable value: ");
value = int.Parse(Console.ReadLine());
Console.WriteLine("New Variable " + varname + " = " + value.ToString());
try { variables.Add(varname, value); }
catch { variables.Remove(varname); variables.Add(varname, value); }
Console.Clear();
break;
case ('b'):
Console.Clear();
variables.Clear();
Console.WriteLine("Enter equation: ");
equation = Console.ReadLine();
equation = equation.Replace(" ", string.Empty);
Console.Clear();
break;
case ('c'):
Console.WriteLine("Equations evaluates to : ");
ExpTree exptree = new ExpTree(equation);
foreach (string key in variables.Keys)
{
exptree.SetVAr(key, variables[key]);
}
Console.WriteLine(exptree.Eval());
Console.WriteLine("Enter any key to continue...");
Console.ReadLine();
Console.Clear();
break;
case ('d'):
equation = string.Empty;
Console.Clear();
break;
case ('e'):
variables.Clear();
Console.Clear();
break;
default:
Console.Clear();
break;
}
}
}