static int RPNStackMaths(object[] RPNEquation)
{
MyStack <int> stack = new MyStack <int>(RPNEquation.Length);
for (int i = 0; i != RPNEquation.Length; i++)
{
if (int.TryParse(RPNEquation[i].ToString(), out int c))
{
stack.Push(c);
}
else
{
int a = stack.Pop();
int b = stack.Pop();
if (RPNEquation[i].ToString() == "+")
{
c = a + b;
}
else if (RPNEquation[i].ToString() == "-")
{
c = a - b;
}
else if (RPNEquation[i].ToString() == "*")
{
c = a * b;
}
else if (RPNEquation[i].ToString() == "/")
{
c = a / b;
}
stack.Push(c);
}
}
int result = stack.Pop();
if (!stack.IsEmpty())
{
throw new InvalidOperationException("Input is not in RPN format");
}
else
{
return(result);
}
}
static object[] ShuntingYardAlgorithm(object[] infixEquation)
{
List <object> output = new List <object> {
};
MyStack <string> operatorStack = new MyStack <string>();
for (int i = 0; i < infixEquation.Length; i++)
{
if (int.TryParse(infixEquation[i].ToString(), out int c))
{
output.Add(infixEquation[i]);
}
else
{
if (infixEquation[i].ToString() == "+")
{
if (operatorStack.IsEmpty())
{
if (operatorStack.Top().ToString() == "*" || operatorStack.Top().ToString() == "/")
{
output.Add(operatorStack.Pop());
}
}
operatorStack.Push("+");
}
else if (infixEquation[i].ToString() == "-")
{
if (operatorStack.IsEmpty())
{
if (operatorStack.Top().ToString() == "*" || operatorStack.Top().ToString() == "/")
{
output.Add(operatorStack.Pop());
}
}
operatorStack.Push("-");
}
else if (infixEquation[i].ToString() == "*")
{
operatorStack.Push("*");
}
else if (infixEquation[i].ToString() == "/")
{
operatorStack.Push("/");
}
else if (infixEquation[i].ToString() == "(")
{
operatorStack.Push("(");
}
else if (infixEquation[i].ToString() == ")")
{
while (operatorStack.Top() != "(")
{
output.Add(operatorStack.Pop());
}
operatorStack.Pop();
}
}
}
while (!operatorStack.IsEmpty())
{
output.Add(operatorStack.Pop());
}
return(output.ToArray());
}