BMH子串查找算法(PHP实现)

interface StringSearchable
{
    public function search($substring,$buffer);
}
class BoyerMooreStringSearchimplements StringSearchable
{
    public $substring =null;
    public $buffer ='';
    public $jumpTable =array();
    protected$results = array();

    public function __construct()
    {   
       
    }
    public function __destruct()
    {
    }
    public function search($substring,$buffer)
    {   
        $this->results= array();
        $this->substring= $substring;
        $this->buffer= $buffer;
        $this->deriveJumpTable();
       
        $substringLen= strlen($this->substring);
        $currentCharIndex= $substringLen- 1;
        $bufferLen= strlen($this->buffer);
        while ($currentCharIndex< $bufferLen) {   
            for ($i= $substringLen- 1;$i >=0; $i--) {
                if ($this->buffer[$currentCharIndex- $substringLen+ $i+ 1]== $this->substring[$i]) {
                    if ($i== 0) {
                        $this->results[]= $currentCharIndex- $substringLen;
                        $currentCharIndex+= $this->getJumpLength($this->buffer[$currentCharIndex]);
                    } else {
                        continue;
                    }
                } else {
                    $currentCharIndex+= $this->getJumpLength($this->buffer[$currentCharIndex]);
                    break;
                }

            }
        }
        return (sizeof($this->results)> 0);
    }
   
    protectedfunction deriveJumpTable()
    {
        $maxJump= strlen($this->substring);
        for ($i= strlen($this->substring)- 2;$i >=0; $i--) {
            if (!array_key_exists($this->substring[$i],$this->jumpTable)) {
                $this->jumpTable[$this->substring[$i]]]= $maxJump- $i-1;
            }
        }
    }
    public function getJumpTable()
    {
        return$this->jumpTable;   
    }
    public function getResults()
    {
        return$this->results;
    }
    public function getResultsCount()
    {
        returnsizeof($this->results);
    }
    public function getJumpLength($charIndex)
    {
        if (array_key_exists($charIndex,$this->jumpTable)) {
            return$this->jumpTable[$charIndex];
        } else {
            returnstrlen($this->substring);
        }
    }
}

function Main()
{   
    $poem = <<<POEM
    you son of bitch
    god damn it
    hey,god love me
    POEM;
    $bm = new BoyerMooreStringSearch();
    $bm->search('god',$poem);
    $count = $bm->getResultsCount;
    echo $count;
}