Fb Challenge

fb.php

<?php
# please use php -f input.php < input00.txt > output00.txt

$stdin = fopen('php://stdin', 'r');
$str = trim(fread($stdin, 1000));
fclose($stdin);

$total = strlen($str);
$count = 0;
$end = $start = 0;

$stack = array();
do {
    $end++;

    $sub = substr($str, $start, $end);

    if ($end >= $total) {
        $start++;
        $end = 0;
    }

    if (!isset($stack[$sub]) && strstr($str, $sub)) {
        $stack[$sub] = true;
        $count ++;
    }
} while($start < $total);

$stdout = fopen('php://stdout', 'w');
fwrite($stdout, $count);
fclose($stdout);