如何在不使用任何内置php函数的情况下搜索字符串中连续重复的字符？

Question

I have been asked to solve this question. Please suggest me how to solve this.

$string = "kkjnmnmnjjjnmn";

here I need to find consecutively repeated string of length 3. for example - kkj has occurred only once and jnm 2 times and nmn 3 times.

Starting from first character, going in right side direction, 3 consecutive characters which are repeated more than once should be the output.

Preg_match_all will result as nmn - 2 times and not as 3 times.

How to solve this?

Answer 1

    $string = "kkjnmnmnjjjnmn";
    $length = strlen($string);
    $pieces = [];
    for ($i = 0; $i < $length - 2; $i++) {
        $piece = substr($string, $i, 3);
        if (array_key_exists($piece, $pieces)) {
            $pieces[$piece] += 1;
        } else {
            $pieces[$piece] = 1;
        }
    }

// $pieces will contain what you need