mathball/lib/padovan/index.js

A JavaScript library for Competitive Programming

"use strict";

/* Padovan Number
 * Function: padovan()
 */

var validate = require("../validation/positive-integer");

function pad(num) {
	var pPrevPrev = 1,
	    pPrev = 1,
	    pCurr = 1,
	    pNext = 1;
	for (var i = 3; i <= num; i++) {
		pNext = pPrevPrev + pPrev;
		pPrevPrev = pPrev;
		pPrev = pCurr;
		pCurr = pNext;
	}
	return pNext;
}

exports.find = function (num) {
	validate(num, "padovan");
	return pad(num);
};