Wordpress, random product only on home search page - php

Question

I have a custom wordpress search page with page navigation numbers, my client asks me to random products on page 1 but not for others, but all products displayed randomly on home page should not displayed on others pages.
For the query i have this code :
$args = array(
'post_type' => 'products',
'paged' => ( get_query_var('paged') ? get_query_var('paged') : 1 )
)
and for the random :
if( $args['paged'] == 1) {
$args['orderby'] = 'rand';
} else {
$args['order'] = 'DESC':
}
the results are there when i do a search, and first page random well, but some products that are already displayed on home page because of the random are also displayed on others pages (ex : page 2 ).
The aim is not display products that are already displayed on home page.
I already do something similar :
if( $page == 1 ) shuffle($r->posts);
But it shuffle only first the 10 products on page 1, and others products on others pages never display on page 1.
After some thoughts i think store first 10 random products to cookie or session and do a NOT IN for others pages ? like this ?
if( $args['paged'] == 1 ){
$args['orderby'] = 'rand';
$r = new Wp_Query($args);
$randomFirstPage = wp_list_pluck( $r->posts, 'ID' );
print_r($randomFirstPage);
setcookie( 'firstPageResults', $randomFirstPage, time()+3600, '/', 'mydomain.com/dev' );
}else{
$not_in = $_COOKIE['firstPageResults'];
$args['NOT IN'] = $not_in;
$r = new Wp_Query($args);
}
Sorry for bad english, and may you help me please ?
Thanks

Answer 1

Try this aproach:
<?php
$products1_ids = array();
$products2_ids = array();
$allproducts = get_posts(array('post_type' => 'products'));
$p=1; foreach($allproducts as $products) {
if(is_page(1) && $p<11) {
$products1_ids[] = $products->ID;
}
if(!is_page(1) && $p>10) {
$products1_ids[] = $products->ID;
}
$p++; }
shuffle($products1_ids);
shuffle($products2_ids);
$post_in = is_page(1) ? $products1_ids : $products2_ids;
$products = new WP_Query(array(
'post_type' => 'products',
'posts_per_page' => 10,
'post__in' => $post_in,
));
if($products->have_posts()) {
while($products->have_posts()) { $products->the_post();
echo '<div class="post">'
the_title();
echo '</div>';
}
}
Hope it helps

Answer 2

Your posted code above uses $args['NOT IN'] = $not_in;, but according to the WP_Query docs the argument to exclude posts by id is post__not_in:
$query = new WP_Query(
array('post_type' => 'post', 'post__not_in' => array(2, 5, 12, 14, 20))
);
So try:
$args['post__not_in'] = $not_in;