<?php
function is_valid($string) {
do {
$string = str_replace(['()', '{}', '[]'], '', $string, $count);
} while ($count);
return (int)!$string;
}
$expressions = array(")(){}", "[]({})", "([])", "{()[]}", "([)]", "{()[]}{()[]}{()[]}{()[]}{()[]}");
foreach ($expressions as $expression) {
echo "$expression is " , is_valid($expression) , "\n";
}
- Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.26, 8.4.1 - 8.4.13
- )(){} is 0
[]({}) is 1
([]) is 1
{()[]} is 1
([)] is 0
{()[]}{()[]}{()[]}{()[]}{()[]} is 1
preferences:
176.92 ms | 408 KiB | 5 Q