/**
 * Part 2.
 * Now there are two image arrays with different "weights", X and Y.  Update your function so there is an X/(X+Y)% chance that
 * each image in the subset is selected from the first array, and a Y/(X+Y)% chance that the image is selected from the second array.
 * The returned subset should still be 1 dimensional, as in part 2.
 * Picking unique images is more important than the weights. i.e. if the subset isn't filled and there are no more images available in X
 * the remaining slots should be drawn exclusively from Y, and vice versa.
 * */

$xImages = array('weight' => 3, 'images' => array('x1.jpg', 'x2.jpg', 'x3.jpg', 'x4.jpg', 'x5.jpg', 'x6.jpg')); //75%
$yImages = array('weight' => 1, 'images' => array('y1.jpg', 'y2.jpg', 'y3.jpg', 'y4.jpg', 'y5.jpg', 'y6.jpg')); //25%
$images = array($xImages, $yImages);

$imageSetWeighted = selectWeighted($images, 6);
echo '6: <pre>' . print_r($imageSetWeighted, true) . '</pre>';
$imageSetWeighted = selectWeighted($images, 8);
echo '8: <pre>' . print_r($imageSetWeighted, true) . '</pre>';
$imageSetWeighted = selectWeighted($images, 16);
echo '16: <pre>' . print_r($imageSetWeighted, true) . '</pre>';

function selectWeighted($images, $number) {

}