<?php
/**
 * 给定一个字符串，请你找出其中不含有重复字符的 最长子串 的长度。
 *
 * @param $s
 *Array
    (
    [a] => 1
    [b] => 2
    [d] => 12
    [e] => 4
    [r] => 5
    [f] => 11
    [s] => 8
    [t] => 9
    )
 *
 *
 * @return bool|string
 */
function lengthOfLongestSubstring($s)
{
    $len  = strlen($s);
    $ans  = 0;
    $i    = 0;
    $data = [];

    for ($j = 0; $j < $len; $j++) {
        $key = $s[$j];
        if (array_key_exists($key, $data)) {
            $i = max($data[$key], $i);
        }
        $ans        = max($ans, $j - $i + 1);
        $data[$key] = $j + 1;
    }
    return $ans;
}

$s = 'abderdfstdfd';
$x = lengthOfLongestSubstring($s);
echo $x;