public static string GetMessage(string message)
{
var output = string.Empty;
var operStack = new Stack <char>();
for (var i = 0; i < message.Length; i++)
{
if (IsDelimeter(message[i]))
{
continue;
}
if (Char.IsDigit(message[i]))
{
while (!IsDelimeter(message[i]) && !IsOperator(message[i]))
{
output += message[i++];
if (i == message.Length)
{
break;
}
}
output += ' ';
i--;
}
if (IsOperator(message[i]))
{
if (message[i] == '-' && output == string.Empty)
{
output += "0 ";
}
if (operStack.Count() > 0)
{
if (message[i] == '-' && operStack.Peek() == '(')
{
output += "0 ";
}
}
switch (message[i])
{
case '(':
operStack.Push(message[i]);
break;
case ')':
{
var s = operStack.Pop();
if (s == '(' && IsOperator(output[output.Length - 1]))
{
output += "0 ";
}
while (s != '(')
{
output += s.ToString() + ' ';
s = operStack.Pop();
}
}
break;
default:
if (operStack.Count > 0)
{
if (GetPriority(message[i]) <= GetPriority(operStack.Peek()))
{
output += operStack.Pop().ToString() + " ";
}
}
operStack.Push(char.Parse(message[i].ToString()));
break;
}
}
}
while (operStack.Count > 0)
{
output += operStack.Pop() + " ";
}
return(output);
}