Add cookie / no-repeat function to random page refresh - arrays

Question

I have been using this java code to call a random html page from a list of 49 on a set timer (or upon page refresh). I would like to convert it so that a cookie - or something else - saves the pages that have already been shown so that upon refresh the user always receives a new page, until the list is finished, at which point the cookie is emptied/deleted.
I found this code for a cookie image array. Could I use it with this? A variant of this also appears here. Apologies, my coding is pretty poor. Any advice appreciated:
<script type="text/javascript">
var sites = [
"name1.html",
"name2.html",
"name3.html",
"name...etc.html",
"name49.html",
]
$(document).ready(function() {
newPage();
});
function newPage()
{
setTimeout(newPage, 60000);
var min = 0;
var max = 48;
var num = Math.floor(Math.random() * (max - min + 1)) + min;
$('#target').attr('src',sites[num]);
}
</script>

Answer 1

var numSites = 49;
var seen = new Array(numSites);
$(document).ready(function() {
var cookie = unescape(getCookie("seen"));
seen = cookie ? cookie.split(',') : seen;
setTimeout(gotoNext, 60000);
});
function gotoNext() {
var num = getRandom();
var count = 0;
while (seen[num] == 1) {
num++;
if (num >= numSites) {
num = 0;
count++;
if (count > 1) {
resetSeen();
num = getRandom();
}
}
}
seen[num] = 1;
setCookie("seen", escape(seen.join(',')), 365);
window.location = "name" + num + ".html";
}
function getCookie(cname) {
var name = cname + "=";
var ca = document.cookie.split(';');
for(var i=0; i<ca.length; i++) {
var c = ca[i].trim();
if (c.indexOf(name)==0) return c.substring(name.length, c.length);
}
return "";
}
function setCookie(cname, cvalue, exdays) {
var d = new Date();
d.setTime(d.getTime() + (exdays*24*60*60*1000));
var expires = "expires=" + d.toGMTString();
document.cookie = cname + "=" + cvalue + "; " + expires;
}
function resetSeen() {
for (var i=0; i<numSites; i++) {
seen[i] = "";
}
}
function getRandom() {
return Math.ceil(Math.random() * numSites);
}

Answer 2

It looks like you're using jQuery so I'll recommend using a jquery plugin for managing cookies much more neatly.
Copy & paste the contents of this URL to a new js file on your server and include it after the jquery file: https://raw.githubusercontent.com/carhartl/jquery-cookie/master/jquery.cookie.js
Or you could possibly use the get/set cookie functions from the other answer you mention.
The main thing to remember is that the cookie is stored as a string so you'll be join()ing and split()ing the array.
The other thing to note is that because we want a random item from the items we haven't visited yet it's more efficient to keep track of those rather than the ones we have visited.
What this means is we always choose a random item from what's left instead of looping over everything and checking each time if we've been there already as that would get very inefficient.
var sites = [ 'name1.html', 'name2.html', 'name3.html', ...etc... ],
unvisited = sites.slice(0); // .slice(0) clones the array
// if the cookie has a value then make it into the unvisited array
if ( $.cookie( 'unvisited' ) )
unvisited = $.cookie( 'unvisited' ).split( ',' );
$(document).ready(function() {
newPage();
});
function newPage() {
setTimeout( newPage, 60000 );
// check if the unvisited array needs resetting
if ( unvisited.length == 0 ) {
unvisited = sites.slice(0);
$.removeCookie( 'unvisited' );
}
// get a new index from the unvisited array
var num = Math.floor( Math.random() * unvisited.length );
// remove the item from the array and save the cookie
var site = unvisited.splice( num, 1 )[ 0 ];
// save the unvisited array minus the site we just spliced out
$.cookie( 'unvisited', unvisited.join( ',' ) );
$( '#target' ).attr( 'src', site );
}