import java.util.Stack;
/**
* Created by gary on 16-1-3.
*/
public class TestStack {
public static void main(String[] args) {
String expression = "(1+((2+3)*(4*5)))";
Stack ops = new Stack<>();
Stack vals = new Stack<>();
for(int i = 0; i < expression.length(); i++) {
char c = expression.charAt(i);
if(c == '(');
else if(c == '+') ops.push(c);
else if(c == '-') ops.push(c);
else if(c == '*') ops.push(c);
else if(c == '/') ops.push(c);
else if(c == ')') {
char op = ops.pop();
Double v = vals.pop();
if(op == '+') v = vals.pop() + v;
if(op == '-') v = vals.pop() - v;
if(op == '*') v = vals.pop() * v;
if(op == '/') v = vals.pop() / v;
vals.push(v);
}
else {
vals.push(Double.parseDouble(String.valueOf(c)));
}
}
System.out.println(vals.pop());
}
}