dluciano/index.html

## index.html
<!doctype html>

<html lang="en">
<head>
  <meta charset="utf-8">

  <title>RPN</title>
  <meta name="description" content="The HTML5 Herald">
  <meta name="author" content="SitePoint">


  <!--[if lt IE 9]>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/html5shiv/3.7.3/html5shiv.js"></script>
  <![endif]-->
</head>

<body>
  <script src="rpn.js"></script>
</body>
</html>

## reverse_polish_notation.js
function node(value){
   var self = this;
   self.value = value;
   self.right = null;
   self.left = null;
   self.hasRight = false;
   self.hasLeft = false;
   self.setLeft = function(n){
     self.hasLeft = true;
     self.left = n;
   };
   self.setRight = function(n){
      self.hasRight = true;
	  self.right = n;
   }
}

function main(){
  var n1 = new node("/");
  var n2 = new node("-");
  var n3 = new node("+");

  var n4 = new node("*");
  var n5= new node(25);

  var n6 = new node(6);
  var n7 = new node("+");

  var n8 = new node(4);
  var n9 = new node(5);

  var n10 = new node(2);
  var n11 = new node(3);

  n1.setLeft(n2);
  n1.setRight(n3);

  n2.setLeft(n4);
  n2.setRight(n5);

  n4.setLeft(n6);
  n4.setRight(n7);

  n7.setLeft(n8);
  n7.setRight(n9);

  n3.setLeft(n10);
  n3.setRight(n11);

  var result = rpn(n1);
  console.log(result);
}

function oper(a, b, operation){
	switch(operation){
		case '+':
			return a + b;
			break;
		case '-':
			return a - b;
			break;
		case '*':
			return a * b;
			break;
		case '/':
			return a / b;
			break;
	}
	throw "Fatal error: unknown operation";
}

function rpn(node){
   var a, b;

   if(node.hasLeft)
      a = rpn(node.left)
   else
      return node.value;

   if(node.hasRight)
      b = rpn(node.right)
   else
      return node.value;

   return oper(a, b, node.value);
}

main();
	<!doctype html>

	<html lang="en">
	<head>
	<meta charset="utf-8">

	<title>RPN</title>
	<meta name="description" content="The HTML5 Herald">
	<meta name="author" content="SitePoint">


	<!--[if lt IE 9]>
	<script src="https://cdnjs.cloudflare.com/ajax/libs/html5shiv/3.7.3/html5shiv.js"></script>
	<![endif]-->
	</head>

	<body>
	<script src="rpn.js"></script>
	</body>
	</html>
	function node(value){
	var self = this;
	self.value = value;
	self.right = null;
	self.left = null;
	self.hasRight = false;
	self.hasLeft = false;
	self.setLeft = function(n){
	self.hasLeft = true;
	self.left = n;
	};
	self.setRight = function(n){
	self.hasRight = true;
	self.right = n;
	}
	}

	function main(){
	var n1 = new node("/");
	var n2 = new node("-");
	var n3 = new node("+");

	var n4 = new node("*");
	var n5= new node(25);

	var n6 = new node(6);
	var n7 = new node("+");

	var n8 = new node(4);
	var n9 = new node(5);

	var n10 = new node(2);
	var n11 = new node(3);

	n1.setLeft(n2);
	n1.setRight(n3);

	n2.setLeft(n4);
	n2.setRight(n5);

	n4.setLeft(n6);
	n4.setRight(n7);

	n7.setLeft(n8);
	n7.setRight(n9);

	n3.setLeft(n10);
	n3.setRight(n11);

	var result = rpn(n1);
	console.log(result);
	}

	function oper(a, b, operation){
	switch(operation){
	case '+':
	return a + b;
	break;
	case '-':
	return a - b;
	break;
	case '*':
	return a * b;
	break;
	case '/':
	return a / b;
	break;
	}
	throw "Fatal error: unknown operation";
	}

	function rpn(node){
	var a, b;

	if(node.hasLeft)
	a = rpn(node.left)
	else
	return node.value;

	if(node.hasRight)
	b = rpn(node.right)
	else
	return node.value;

	return oper(a, b, node.value);
	}

	main();