private double Calculate(IEnumerable <ContentElement> input)
{
Stack <ContentElement> stack = new Stack <ContentElement>();
Queue <ContentElement> queue = new Queue <ContentElement>(ConvertToPostfixNotation(input));
ContentElement firstInQuene = queue.Dequeue();
double returnValue = 0;
double summ;
if (queue.Count == 0)
{
if (firstInQuene.IsIndex())
{
returnValue = DigitValue(new CellIndex(firstInQuene.Text()));
}
else
{
returnValue = firstInQuene.Value();
}
}
else
{
while (queue.Count >= 0)
{
if (!firstInQuene.IsOperators())
{
stack.Push(firstInQuene);
firstInQuene = queue.Dequeue();
}
else
{
ContentElement firstEl = stack.Pop();
ContentElement secondEl = stack.Pop();
summ = MathOp(firstEl, secondEl, firstInQuene);
stack.Push(new DigitElement(summ.ToString()));
if (queue.Count > 0)
{
firstInQuene = queue.Dequeue();
}
else
{
break;
}
}
}
returnValue = stack.Pop().Value();
}
return(returnValue);
}
