multi-range-diff.php

<?php
	
	// @ref https://twitter.com/brendt_gd/status/1065534180266782721
	
	$a = range(5, 8);
	$b = range(13,16);
	$c = range(1,3);
		
	$current = range(1,16);
	
	$a = array_combine($a, array_fill(0, sizeof($a), 1)) + array_combine($current, array_fill(0, sizeof($current), 0));
	$b = array_combine($b, array_fill(0, sizeof($b), 1)) + array_combine($current, array_fill(0, sizeof($current), 0));
	$c = array_combine($c, array_fill(0, sizeof($c), 1)) + array_combine($current, array_fill(0, sizeof($current), 0));
	
	$diff = [];
	foreach ($current as $index) {
		if ($a[$index] xor $b[$index] xor $c[$index] xor 1) {
			$diff[] = $index;
		}
	}
	
	var_dump(implode(',', $diff)); // 4,9,10,11,12