private static String InfixToPostfix(string infix)
{
String postfix = "";
var st = new StackArray <char>(20);
char next, symbol;
for (int i = 0; i < infix.Length; i++)
{
symbol = infix[i];
if (symbol == ' ' || symbol == '\t')
{
continue;
}
switch (symbol)
{
case '(':
st.Push(symbol);
break;
case ')':
while ((next = st.Pop()) != '(')
{
postfix = postfix + next;
}
break;
case '+':
case '-':
case '*':
case '/':
case '%':
case '^':
while (!st.IsEmpty() && Precedence(st.Peek()) >= Precedence(symbol))
{
postfix = postfix + st.Pop();
}
st.Push(symbol);
break;
default: //hopefully an operand
postfix = postfix + symbol;
break;
}
}
while (!st.IsEmpty())
{
postfix = postfix + st.Pop();
}
return(postfix);
}
public static int EvaluatePostfix(String postfix)
{
var st = new StackArray <int>(50);
int x, y;
for (int i = 0; i < postfix.Length; i++)
{
if (Char.IsDigit(postfix[i]))
{
st.Push(Convert.ToInt32(Char.GetNumericValue(postfix[i])));
}
else
{
x = st.Pop();
y = st.Pop();
switch (postfix[i])
{
case '+':
st.Push(y + x);
break;
case '-':
st.Push(y - x);
break;
case '*':
st.Push(y * x);
break;
case '/':
st.Push(y / x);
break;
case '%':
st.Push(y % x);
break;
case '^':
st.Push(power(y, x));
break;
}
}
}
return(st.Pop());
}
