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run code in 150+ php & hhvm versions
Bugs & Features
<?php $input = "hey"; function string_getpermutations($prefix, $characters, &$permutations) { if (count($characters) == 1) $permutations[] = $prefix . array_pop($characters); else { for ($i = 0; $i < count($characters); $i++) { $tmp = $characters; unset($tmp[$i]); string_getpermutations($prefix . $characters[$i], array_values($tmp), $permutations); } } } $characters = array(); for ($i = 0; $i < strlen($input); $i++) $characters[] = $input[$i]; $permutations = array(); print_r($characters); string_getpermutations("", $characters, $permutations); print_r(sort($permutations));
Output for 4.3.0 - 7.1.0
Array ( [0] => h [1] => e [2] => y ) 1