/*
* Problem statement:
* 1+2*3
* Optimal solution is to use polymorphism, design ValueNode, OpNode, AdditionNode, MultiplcationNode classes.
* Naive solution (most people do) is to use a lot of conditionals
* Pseudo code as following:
*
*
* Google talk:
* https://www.youtube.com/watch?v=4F72VULWFvc
* Reference:
* http://juliachencoding.blogspot.ca/2015/11/the-clean-code-talks.html
*
* +
* / \
* 1 *
* / \
* 2 3
*/
static void Main(string[] args)
{
//string input = "1+2*3";
Node n1 = new Node("+");
n1.left = new Node("1");
n1.right = new Node("*");
n1.right.left = new Node("2");
n1.right.right = new Node("3");
double result = calculate(n1);
Console.WriteLine("Test result is "+result.ToString());
}
public static double calculate(Node root)
{
if (root == null) return 0;
return root.evaluate();
}