Assigned Th 6/26/2008, due Fr 7/4 at 9pm. 50 points.
http://www.cs.nyu.edu/courses/summer08/G22.3033-002/
Homeworks are due on Fridays at 9pm. This deadline will be strictly enforced.
Email your answers to Robert Soulé robert.soule@gmail.com. Please put your solutions to VBA programming problems in a powerpoint presentation. For all other questions (including programming problems in other languages), just send a simple text file, such as what you get when using Emacs, Vi, Notepad, or the "save as text only" feature in Word.
Please make sure that your code works with the compilers and tools installed at CIWW. Specifically, please test:
doowop1
(see http://www.cims.nyu.edu/systems/resources/computeservers/).
(2+4+4+4 = 14 points) Consider the following HTML document with JavaScript.
<html><head>
<meta http-equiv="Content-Script-Type" content="text/javascript" />
<script>
function curry(f, x) {
return function(y) {
return f(x, y);
}
}
</script>
</head><body>
<h1><a href="http://en.wikipedia.org/wiki/Currying">Currying</a></h1>
<script>
function add(x,y){ return x + y; }
var inc = curry(add, 1);
var double = curry(function(x,y){ return x * y; }, 2);
document.write(inc(5) + "<br/>\n");
document.write(double(5) + "<br/>\n");
</script>
</body></html>
inc,
what is the function, and what is the environment? And in the
environment, what is f bound to, and what is x bound to?
double, what is the function, and what is the
environment? And in the environment, what is f bound to, and what
is x bound to?
curry to create a closure for squaring a
number. For example, square(5) should return 25.
(2+4+4 = 10 points) Consider the following HTML document with JavaScript.
<html><head>
<meta http-equiv="Content-Script-Type" content="text/javascript" />
<script>
function C() { }
C.prototype.f = function() { return 'Cf'; }
C.prototype.g = function() { return 'Cg'; }
C.prototype.h = function() { return 'Ch'; }
function D() { }
D.prototype = new C();
D.prototype.constructor = D;
D.prototype.g = function() { return 'Dg'; }
function E() { }
E.prototype = new D();
E.prototype.constructor = E;
E.prototype.h = function() { return 'Eh'; }
</script>
</head><body>
<script>
var x = new D();
document.write(x.f() + ', ' + x.g() + ', ' + x.h() + "\n<br/>");
var y = new E();
document.write(y.f() + ', ' + y.g() + ', ' + y.h() + "\n<br/>");
</script>
</body></html>
x?
y?
(12 points) Write an HTML document with a form that has two text input fields and two buttons. When the user enters a value in the “Celsius” field and presses the “To Fahrenheit” button, that should trigger a JavaScript event handler that shows the converted temperature in the “Fahrenheit” input field. Likewise, when the user enters a value in the “Fahrenheit” field and presses the “To Celsius” button, that should trigger a JavaScript event handler that shows the converted temperature in the “Celsius” input field. Below is an example screen shot. Remember to test your code in both the Mozilla Firefox and the Microsoft Internet Explorer web browsers.
(14 points) Write a constructor PriorityQueue that creates an object
that supports three methods: push, pop, and peek. A
priority queue allows elements to be added in any order, but always
returns the smallest element. The push method adds an element to
the queue. The pop method removes and returns the smallest
element in the queue. The peek method also returns the smallest
element in the queue, but does not remove it. If you put your code in a
file called PriorityQueue.js, then you can test it with the following
driver:
<html><head>
<meta http-equiv="Content-Script-Type" content="text/javascript" />
<script src="PriorityQueue.js"></script>
<script>
var q = new PriorityQueue();
function doPush() {
var val = document.driver.push.value;
q.push(val);
var log = document.getElementById("log");
log.innerHTML += "push(" + val + ")\n<br/>";
}
function doPop() {
var val = q.pop();
var log = document.getElementById("log");
log.innerHTML += "pop() -> " + val + "\n<br/>";
}
function doPeek() {
var val = q.peek();
var log = document.getElementById("log");
log.innerHTML += "peek() -> " + val + "\n<br/>";
}
</script>
</head><body>
<form name="driver">
<input type="text" name="push">
<input type="button" value="Push" onclick="doPush();">
<br/>
<td><input type="button" value="Pop" onclick="doPop();">
<br/>
<td><input type="button" value="Peek" onclick="doPeek();">
</form>
<span id="log"></span>
</body></html>
The following screen snapshot demonstrates the behavior of a priority queue through a sequence of calls.
