<?php
$vendors = ["Amazon", "Newegg", "Frys"];
$products = ['a', 'b'];
$combinations = array();
// Algorithm to generate all combinations of a specific size from an array of possible values
function sampling($chars, $size, $combinations = array()) {
# if it's the first iteration, the first set
# of combinations is the same as the set of characters
if (empty($combinations)) {
$combinations = $chars;
}
# we're done if we're at size 1
if ($size == 1) {
return $combinations;
}
# initialise array to put new values in
$new_combinations = array();
# loop through existing combinations and character set to create strings
foreach ($combinations as $combination) {
foreach ($chars as $char) {
$new_combinations[] = $combination . $char;
}
}
# call same function again for the next iteration
return sampling($chars, $size - 1, $new_combinations);
}
// Build vendor combinations as a function of the number of products. Example with 5 products:
// ['Amazon', 'Amazon', 'Amazon', 'Newegg', 'Newegg']
$combinations = sampling($vendors, count($products));
foreach ($combinations as $key => $combination) {
// Calculate the total price
var_dump($combination);
}