public double Evaluate(List <string> operandsList)
{
foreach (char exp in Expression)
{
_queue.EnQueue(exp);
}
while (!_queue.IsEmpty())
{
var deQueued = (char)_queue.DeQueue();
if (deQueued > 96 && deQueued < 123)
{
var valueString = operandsList.FirstOrDefault(x => x.Contains(deQueued.ToString()));
_stack.Push(double.Parse(valueString.Split(' ')[1]));
}
else
{
var valueA = (double)_stack.Pop();
var valueB = (double)_stack.Pop();
switch (deQueued)
{
case '+':
_stack.Push(valueA + valueB);
break;
case '-':
_stack.Push(valueA - valueB);
break;
case '/':
_stack.Push(valueA / valueB);
break;
case '*':
_stack.Push(valueA * valueB);
break;
}
}
}
return((double)_stack.Pop());
}
public PostFix ToPostFix()
{
List <char> operatorsList = new List <char>()
{
'+', '-', '*', '/'
};
List <char> additiveOp = new List <char>()
{
'+', '-'
};
List <char> multiplicativeOp = new List <char>()
{
'*', '/'
};
string returnString = "";
foreach (char input in Expression) //7
{
if (input > 96 && input < 123) //2
{
_queue.EnQueue(input);
continue;
}
if (input == '(') //3
{
_stack.Push(input);
continue;
}
if (input == ')') //4
{
while ((char)_stack.Peek() != '(')
{
_queue.EnQueue(_stack.Pop());
}
_stack.Pop();
continue;
}
if (operatorsList.Contains(input) && (_stack.GetSize() == 0 || (char)_stack.Peek() == '(')) //5
{
_stack.Push(input);
continue;
}
while (!_stack.IsEmpty() && (additiveOp.Contains(input) && multiplicativeOp.Contains((char)_stack.Peek()))) //6
{
if (operatorsList.Contains(input) && !_stack.IsEmpty())
{
if (additiveOp.Contains(input) && multiplicativeOp.Contains((char)_stack.Peek()))
{
_queue.EnQueue(_stack.Pop());
}
else
{
_stack.Push(input);
}
}
}
}
while (!_stack.IsEmpty())
{
_queue.EnQueue(_stack.Pop());
}
while (!_queue.IsEmpty())
{
returnString += _queue.DeQueue();
}
return(new PostFix(returnString));
}
