//Part 2: Complete this method to evaluate Postfix Expressions using MyListStack
static int EvaluatePostFix(string[] stringItems, MyListStack stack)
{
// Cycle through string array for various operations
for (int i = 0; i < stringItems.Length; i++)
{
int temp;
bool isNumeric = int.TryParse(stringItems[i], out temp);
if (isNumeric) // if index is a number
{
stack.Push(temp);
}
else // if index is an operation
{
int first = stack.Pop();
int second = stack.Pop();
int total = 0;
// Switch for mathematic operations
switch (stringItems[i])
{
case "+":
total = first + second;
Console.Write("(" + first + " + " + second + ")\n");
stack.Push(total);
break;
case "-":
total = first - second;
Console.Write("(" + first + " - " + second + ")\n");
stack.Push(total);
break;
case "*":
total = first * second;
Console.Write("(" + first + " * " + second + ")\n");
stack.Push(total);
break;
case "/":
total = first / second;
Console.Write("(" + first + " / " + second + ")\n");
stack.Push(total);
break;
case "%":
total = first % second;
Console.Write("(" + first + " % " + second + ")\n");
stack.Push(total);
break;
} // switch
} // else
} // for
return(stack.Pop());
}
