Finding_PPTs.js

// FOR THE PURPOSES of this code sample, some code essential 
// for the functioning of this script was removed.
// Please view the "Finding PPTs" page source of 
// http://pramodk.net/GT/MATH2803/PPTs/ 
// to see a functional example.

$("input[name='submit']").click(function () {   // Upon clicking the submit button, run this function

	// Get the input values
	var maxS = $("input[name='s_bound']").val();
	var maxT = $("input[name='s_bound']").val();

	// Return if there is invalid data
	if ((maxS === 0 || maxS === "") || (maxT === 0 || maxT === "")) {
		alert("One (or both) of your value(s) is/are invalid or null. Please enter a value or larger number and submit again.");
		return;
	}

	// Empty the current table contents
	$("#PPTs tbody").empty();

	// START: helper functions
	// Helper: check if number is integer
	var isInt = function(n) {
		if (n % 1 === 0) {
			return true;
		}
		return false;
	};
	// Helper: find GDC of two numbers (i.e. check if they are coprime)
	var gcd = function(a, b) {
		if (!b) {
			return a;
		}

		return gcd(b, a % b);
	};
	// Main helper: get PPT from s and t values; returns PPT only if it is valid
	var getPPT = function(s, t) {
		var a = Math.abs((Math.pow(t, 2) - Math.pow(s, 2)));
		var b = 2 * s * t;
		var c = (Math.pow(s, 2) + Math.pow(t, 2));

		// return false if any value is 0, just for simplicity
		if ((a === 0) || (b === 0) || (c === 0)) {
			return false;
		}
		// Check if a and c are integers, check coprime of one pair, check Pythagorean Theorem
		else if (isInt(a) && isInt(c) && (gcd(a, b) === 1) && (Math.pow(a, 2) + Math.pow(b, 2) === Math.pow(c, 2))) {
			return new Array(a, b, c);
		}
		return false;
	};
	// END: helper functions

	// Declare new array of PPTs
	var PPTs = new Array();
	// For all s and t values less than or equal to the maxS and maxT values, respectively, try to get a PPT for s and t
	for (var s = 0; s <= maxS; s++) {
		for (var t = 0; t <= maxT; t++) {
			var PPT = getPPT(s, t);
			if (PPT && (JSON.stringify(PPTs).indexOf(JSON.stringify(PPT)) === -1)) {    // This searching method could be better :)
				PPTs.push(PPT);     // Our continously expanding array of valid PPTs
			}
		}
	}

	// Append rows to our table
	for (var i = 0; i < PPTs.length; i++) {
		$("#PPTs tbody").append("<tr><td>" + PPTs[i][0] + "</td><td>" + PPTs[i][1] + "</td><td>" + PPTs[i][2] + "</td></tr>");
	}
}

// JavaScript and logic by Pramod Kotipalli (pramodk.net)
// Created for Matthew Baker's course
// (Math 2803: Number Theory and Cryptography)
// at the Georgia Institute of Technology
// --------------------------------------------------------
// Use freely under these conditions:
//      Attribution-NonCommercial 4.0 International
//      (http://creativecommons.org/licenses/by-nc/4.0/)
// --------------------------------------------------------