「第14回オフラインリアルタイムどう書くの参考問題」をPHPで解く

<?php
    class CROSSCIRCLE{
        /**
        * 円周上のCrossing
        * @param String 「aabbca1bcb」みたいな文字列
        * @return int 「14」みたいな数値
        */
        public function get($input){
            // 初期値
            $count = 0;

            // 頭からくるくる
            for($i=0; $i<strlen($input)-1; $i++){
                $pos = $i+2;
                // 先に同じ文字が見つかれば
                while(($pos = strpos($input, $input[$i], $pos)) !== false){
                    // 該当の文字で左右に区切る
                    $c1 = count_chars(substr($input, $i+1, $pos-$i-1), 1);
                    $c2 = count_chars(substr_replace($input, '', $i, $pos-$i+1), 1);
                    // 左右に同じ文字があれば、文字数の積が交点の数
                    foreach($c1 as $key=>$val){
                        if(isset($c2[$key])){
                            $count += $val*$c2[$key];
                        }
                    }
                    $pos++;
                }
            }
            // 半分
            return $count/2;
        }
    }

    // 以下はテスト
    $test = [
        ['aabbca1bcb', '14'],
        ['111ZZZ', '0'],
        ['v', '0'],
        ['ww', '0'],
        ['xxx', '0'],
        ['yyyy', '1'],
        ['zzzzz', '5'],
        ['abcdef', '0'],
        ['abcaef', '0'],
        ['abbaee', '0'],
        ['abcacb', '2'],
        ['abcabc', '3'],
        ['abcdabcd', '6'],
        ['abcadeabcade', '23'],
        ['abcdeedcba', '0'],
        ['abcdeaedcba', '8'],
        ['abcdeaedcbad', '16'],
        ['QQQQXXXX', '2'],
        ['QwQQmQXmXXwX', '14'],
        ['111222333', '0'],
        ['aaAAaA', '4'],
        ['121232313', '12'],
        ['1ab1b', '1'],
        ['abcdefbadcfe', '12'],
        ['abxcdefbadcfex', '14'],
        ['dtnwtkt', '0'],
        ['mvubvpp', '0'],
        ['moggscd', '0'],
        ['kzkjzpkw', '2'],
        ['fbifybre', '1'],
        ['rrrfjryki', '1'],
        ['wrbbdwsdwtx', '2'],
        ['vvucugvxbvgx', '9'],
        ['ojkjzyasjwbfjj', '5'],
        ['ggffyuxnkyypifff', '5'],
        ['vcgtcqlwrepwvkkogl', '4'],
        ['xeqtmmgppwcjpcisogxbs', '4'],
        ['lukltpeucrqfvcupnpxwmoj', '6'],
        ['zpzswlkkoqwwndwpfdpkhtzgtn', '31'],
        ['bkfeflagfvluelududqjcvfyvytfw', '45'],
        ['rvqbhfmcjjqlpqzulzerxgyowiwrfkmhw', '26'],
        ['qyxvpdtoeexbqsethwjwmqszcxxjnsdoeaet', '144'],
        ['rjmsgmswhcolmpbhmpncziymydyalrcnevsrespj', '133'],
        ['oxetnyjzjbysnwktfwzndlejfndsqeetsnjvsicyjehd', '395'],
        ['wzvddnddzogywcqxbyvagbzmsmtcmrrlbnebmvhaemjouaqim', '219'],
        ['karhphxcxqgsyorhusbumbqzocuzvnwzwcpxgsksrviihxrgsrhji', '461'],
        ['oxgbononhqdxzmkysgijwvxljpaazmgkurkpffeuwywwuyxhyfkicgyzyc', '441'],
        ['sdgsrddwsrwqthhdvhrjhgtxwgurgyiygtktgtughtogzaqmcafkljgpniddsvb', '1077'],
        ['qemhecchkgzhxmdcsltwhpoyhkapckkkzosmklcvzkiiucrvzzznmhjfcdumuflavxik', '1711'],
        ['ffqmsirwpxrzfkbvmmfeptkbhnrvfcywthkwkbycmayhhkgvuyecbwwofwthlmzruphrcujwhr', '2440'],
    ];

    $crosscircle = new CROSSCIRCLE();
    foreach($test as $key=>$data){
        $answer = $crosscircle->get($data[0]);
        if($answer !== (int)$data[1]){
            print('えらー');
        }
    }